libinput-seat: allow setting libinput log priority in weston

Look for WESTON_LIBINPUT_LOG_PRIORITY environment variable.  If
it exists then use it to set the libinput log priority.
Otherwise, don't set the priority and get whatever libinput's
default priority is.

Setting WESTON_LIBINPUT_LOG_PRIORITY=0 allows us to log which
input devices are detected at Weston startup and makes it a
little more consistent with Weston's original evdev input setup
log messages... and useful for debugging and testing.

Signed-off-by: U. Artie Eoff <ullysses.a.eoff@intel.com>

src/libinput-seat.c

@@ -262,12 +262,19 @@ int
 udev_input_init(struct udev_input *input, struct weston_compositor *c, struct udev *udev,
 		const char *seat_id)
 {
+	const char *log_priority = NULL;
+
 	memset(input, 0, sizeof *input);
 
 	input->compositor = c;
 
 	libinput_log_set_handler(&libinput_log_func, NULL);
 
+	log_priority = getenv("WESTON_LIBINPUT_LOG_PRIORITY");
+	if (log_priority) {
+		libinput_log_set_priority(strtol(log_priority, NULL, 10));
+	}
+
 	input->libinput = libinput_udev_create_for_seat(&libinput_interface, input,
 							udev, seat_id);
 	if (!input->libinput) {