Add LIBUSB_CALL where needed to avoid warnings such as the following:
In file included from src/hardware/hantek-dso/api.c:34:0:
src/hardware/hantek-dso/dso.h:212:13:
note: expected 'libusb_transfer_cb_fn' but argument is of type 'void (*)(struct libusb_transfer *)'
SR_PRIV int dso_get_channeldata(const struct sr_dev_inst *sdi,
^
(lwla_convert_trigger): Fix trigger mask computation bug introduced
by recent change: Widen constant to 64 bit before shifting so that
channel nunmbers beyond 32 are processed correctly.