media: usb: gspca: add a missed check for goto_low_power

The fix checks if goto_low_power() fails, and if so, issues an error
message.
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/usb/gspca/cpia1.c

@@ -1434,6 +1434,7 @@ static int sd_config(struct gspca_dev *gspca_dev,
 {
 	struct sd *sd = (struct sd *) gspca_dev;
 	struct cam *cam;
+	int ret;
 
 	sd->mainsFreq = FREQ_DEF == V4L2_CID_POWER_LINE_FREQUENCY_60HZ;
 	reset_camera_params(gspca_dev);
@@ -1445,7 +1446,10 @@ static int sd_config(struct gspca_dev *gspca_dev,
 	cam->cam_mode = mode;
 	cam->nmodes = ARRAY_SIZE(mode);
 
-	goto_low_power(gspca_dev);
+	ret = goto_low_power(gspca_dev);
+	if (ret)
+		gspca_err(gspca_dev, "Cannot go to low power mode: %d\n",
+			  ret);
 	/* Check the firmware version. */
 	sd->params.version.firmwareVersion = 0;
 	get_version_information(gspca_dev);