V4L/DVB (9190): ivtv: yuv write() error handling tweak

Modifies behaviour of a failed dma write() operation for the yuv device.
If the dma transfer for the yuv device fails, the write() operation will now
exit immediately.
Signed-off-by: Ian Armstrong <ian@iarmst.demon.co.uk>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/ivtv/ivtv-fileops.c

@@ -600,13 +600,14 @@ ssize_t ivtv_v4l2_write(struct file *filp, const char __user *user_buf, size_t c
 	since we may get here before the stream has been fully set-up */
 	if (mode == OUT_YUV && s->q_full.length == 0 && itv->dma_data_req_size) {
 		while (count >= itv->dma_data_req_size) {
-			if (!ivtv_yuv_udma_stream_frame (itv, (void __user *)user_buf)) {
+			rc = ivtv_yuv_udma_stream_frame(itv, (void __user *)user_buf);
+
+			if (rc < 0)
+				return rc;
+
 			bytes_written += itv->dma_data_req_size;
 			user_buf += itv->dma_data_req_size;
 			count -= itv->dma_data_req_size;
-			} else {
-				break;
-			}
 		}
 		if (count == 0) {
 			IVTV_DEBUG_HI_FILE("Wrote %d bytes to %s (%d)\n", bytes_written, s->name, s->q_full.bytesused);