Use line-buffering on stdout, regardless of the output device.

ui/main.c

@@ -342,6 +342,11 @@ int main(int argc, char **argv)
 	struct cmdline_args args = {0};
 	int ret = 0;
 
+	/* Line buffering is required for tools which read mspdebug's
+	 * output (like msp430eclipse).
+	 */
+	setvbuf(stdout, NULL, _IOLBF, 0);
+
 	opdb_reset();
 	ctrlc_init();