V4L/DVB (10463): radio-mr800: fix checking of retval after usb_bulk_msg

Patch corrects checking of returned value after usb_bulk_msg. Now we
also check if number of transferred bytes equals to BUFFER_LENGTH.
Signed-off-by: Alexey Klimov <klimov.linux@gmail.com>
Signed-off-by: Douglas Schilling Landgraf <dougsland@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/radio/radio-mr800.c

@@ -214,7 +214,7 @@ static int amradio_set_mute(struct amradio_device *radio, char argument)
 	retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
 		(void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);
 
-	if (retval) {
+	if (retval < 0 || size != BUFFER_LENGTH) {
 		mutex_unlock(&radio->lock);
 		return retval;
 	}
@@ -251,7 +251,7 @@ static int amradio_setfreq(struct amradio_device *radio, int freq)
 	retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
 		(void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);
 
-	if (retval) {
+	if (retval < 0 || size != BUFFER_LENGTH) {
 		mutex_unlock(&radio->lock);
 		return retval;
 	}
@@ -268,7 +268,7 @@ static int amradio_setfreq(struct amradio_device *radio, int freq)
 	retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
 		(void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);
 
-	if (retval) {
+	if (retval < 0 || size != BUFFER_LENGTH) {
 		mutex_unlock(&radio->lock);
 		return retval;
 	}