media: media/saa7146: fix incorrect assertion in saa7146_buffer_finish

In saa7146_buffer_finish, the code for q->curr to be NULL is
already present and asserting for NULL is unnecessary. This patch
elimiates such a check.
Signed-off-by: Aditya Pakki <pakki001@umn.edu>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/common/saa7146/saa7146_fops.c

@@ -97,8 +97,6 @@ void saa7146_buffer_finish(struct saa7146_dev *dev,
 	DEB_EE("dev:%p, dmaq:%p, state:%d\n", dev, q, state);
 	DEB_EE("q->curr:%p\n", q->curr);
 
-	BUG_ON(!q->curr);
-
 	/* finish current buffer */
 	if (NULL == q->curr) {
 		DEB_D("aiii. no current buffer\n");