V4L/DVB (9911): em28xx: vidioc_try_fmt_vid_cap() doesn't need any lock

vidioc_try_fmt_vid_cap() just checks if a given resolution is supported.
It doesn't touch on struct em28xx device descriptor. so, there's no need
to lock.

While there, use unlikely() for those values that aren't likely to
occur.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/em28xx/em28xx-video.c b/drivers/media/video/em28xx/em28xx-video.c
index 2d88afe..1681af1 100644
--- a/drivers/media/video/em28xx/em28xx-video.c
+++ b/drivers/media/video/em28xx/em28xx-video.c
@@ -730,19 +730,17 @@
 	/* width must even because of the YUYV format
 	   height must be even because of interlacing */
 	height &= 0xfffe;
-	width &= 0xfffe;
+	width  &= 0xfffe;
 
-	if (height < 32)
+	if (unlikely(height < 32))
 		height = 32;
-	if (height > maxh)
+	if (unlikely(height > maxh))
 		height = maxh;
-	if (width < 48)
+	if (unlikely(width < 48))
 		width = 48;
-	if (width > maxw)
+	if (unlikely(width > maxw))
 		width = maxw;
 
-	mutex_lock(&dev->lock);
-
 	if (dev->board.is_em2800) {
 		/* the em2800 can only scale down to 50% */
 		if (height % (maxh / 2))
@@ -772,7 +770,6 @@
 	f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
 	f->fmt.pix.field = V4L2_FIELD_INTERLACED;
 
-	mutex_unlock(&dev->lock);
 	return 0;
 }