Various errno/strerror() related fixes.

- Don't #include <errno.h> in files that don't actually need it.

 - Don't use strerror() on error codes from functions that don't set
   errno. Replace strerror() with sr_strerror() for libsigrok functions.

src/hardware/agilent-dmm/api.c

@@ -22,7 +22,6 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <string.h>
-#include <errno.h>
 #include "libsigrok.h"
 #include "libsigrok-internal.h"
 #include "agilent-dmm.h"

src/hardware/agilent-dmm/sched.c

@@ -20,7 +20,6 @@
 #include <glib.h>
 #include <stdlib.h>
 #include <string.h>
-#include <errno.h>
 #include <math.h>
 #include "libsigrok.h"
 #include "libsigrok-internal.h"

src/hardware/atten-pps3xxx/api.c

@@ -18,7 +18,6 @@
  */
 
 #include <string.h>
-#include <errno.h>
 #include "protocol.h"
 
 /*
@@ -142,7 +141,7 @@ static GSList *scan(struct sr_dev_driver *di, GSList *options, int modelid)
 	memset(packet, 0, PACKET_SIZE);
 	if ((ret = serial_read_nonblocking(serial, packet, PACKET_SIZE)) < 0) {
 		sr_err("Unable to read while probing for hardware: %s",
-				strerror(errno));
+				sr_strerror(ret));
 		return NULL;
 	}
 	if (ret != PACKET_SIZE || packet[0] != 0xaa || packet[1] != 0xaa) {

src/hardware/atten-pps3xxx/protocol.c

@@ -18,7 +18,6 @@
  */
 
 #include <string.h>
-#include <errno.h>
 #include "protocol.h"
 
 static void dump_packet(char *msg, uint8_t *packet)

src/hardware/beaglelogic/protocol.c

@@ -17,7 +17,6 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include <errno.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>

src/hardware/colead-slm/api.c

@@ -21,7 +21,6 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
-#include <errno.h>
 #include <string.h>
 #include "libsigrok.h"
 #include "libsigrok-internal.h"

src/hardware/colead-slm/protocol.c

@@ -19,7 +19,6 @@
 
 #include <stdlib.h>
 #include <glib.h>
-#include <errno.h>
 #include <string.h>
 #include "libsigrok.h"
 #include "libsigrok-internal.h"

src/hardware/conrad-digi-35-cpu/protocol.h

@@ -27,7 +27,6 @@
 #define LIBSIGROK_HARDWARE_CONRAD_DIGI_35_CPU_PROTOCOL_H
 
 #include <stdint.h>
-#include <errno.h>
 #include <string.h>
 #include <glib.h>
 #include "libsigrok.h"

src/hardware/fluke-dmm/api.c

@@ -22,7 +22,6 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <string.h>
-#include <errno.h>
 #include "libsigrok.h"
 #include "libsigrok-internal.h"
 #include "fluke-dmm.h"

src/hardware/fluke-dmm/fluke.c

@@ -20,7 +20,6 @@
 #include <stdlib.h>
 #include <math.h>
 #include <string.h>
-#include <errno.h>
 #include <glib.h>
 #include "libsigrok.h"
 #include "libsigrok-internal.h"

src/hardware/motech-lps-30x/api.c

@@ -24,7 +24,6 @@
  */
 
 #include <ctype.h>
-#include <errno.h>
 #include <math.h>
 #include <string.h>
 #include "protocol.h"
@@ -285,15 +284,16 @@ SR_PRIV int lps_process_status(struct sr_dev_inst* sdi, int stat)
 SR_PRIV int lps_query_status(struct sr_dev_inst* sdi)
 {
 	char buf[LINELEN_MAX];
-	int stat;
+	int stat, ret;
 	struct dev_context* devc;
 
 	devc = (struct dev_context*)sdi->priv;
 
 	devc->req_sent_at = g_get_real_time();
 
-	if (lps_cmd_reply(buf, sdi->conn, "STATUS") < 0) {
-		sr_err("%s: Failed to read status: %d %s", __func__, errno, strerror(errno));
+	if ((ret = lps_cmd_reply(buf, sdi->conn, "STATUS")) < 0) {
+		sr_err("%s: Failed to read status: %s.", __func__,
+			sr_strerror(ret));
 		return SR_ERR;
 	}
 
@@ -379,7 +379,7 @@ static GSList *do_scan(lps_modelid modelid, struct sr_dev_driver *drv, GSList *o
 	struct sr_channel_group *cg;
 	GSList *devices;
 	const char *conn, *serialcomm;
-	int cnt;
+	int cnt, ret;
 	gchar buf[LINELEN_MAX];
 	gchar channel[10];
 	char *verstr;
@@ -434,7 +434,7 @@ static GSList *do_scan(lps_modelid modelid, struct sr_dev_driver *drv, GSList *o
 
 	/* Query version */
 	verstr = NULL;
-	if (lps_cmd_reply(buf, serial, "VERSION") == SR_OK) {
+	if ((ret = lps_cmd_reply(buf, serial, "VERSION")) == SR_OK) {
 		if (strncmp(buf, "Ver-", 4)) {
 			sr_spew("Version string %s not recognized.", buf);
 			goto exit_err;
@@ -445,7 +445,8 @@ static GSList *do_scan(lps_modelid modelid, struct sr_dev_driver *drv, GSList *o
 	}
 	else  /* Bug in device FW 1.17: Querying version string fails while output is active.
 		Therefore just print an error message, but do not exit with error. */
-		sr_err("Failed to query for hardware version: %d %s", errno, strerror(errno));
+		sr_err("Failed to query for hardware version: %s.",
+			sr_strerror(ret));
 
 	sdi = g_malloc0(sizeof(struct sr_dev_inst));
 	sdi->status = SR_ST_INACTIVE;

src/hardware/norma-dmm/protocol.h

@@ -23,7 +23,6 @@
 #include <stdint.h>
 #include <string.h>
 #include <ctype.h>
-#include <errno.h>
 #include <math.h>
 #include <glib.h>
 #include "libsigrok.h"

src/hardware/serial-dmm/api.c

@@ -23,7 +23,6 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <string.h>
-#include <errno.h>
 #include <glib.h>
 #include "libsigrok.h"
 #include "libsigrok-internal.h"

src/hardware/serial-dmm/protocol.c

@@ -21,7 +21,6 @@
 #include <stdlib.h>
 #include <math.h>
 #include <string.h>
-#include <errno.h>
 #include <glib.h>
 #include "libsigrok.h"
 #include "libsigrok-internal.h"