V4L/DVB (13596): ov511.c typo: lock => unlock

V4L/DVB (13596): ov511.c typo: lock => unlock

commit 50e9d31183ed61c787b870cb3ee8f6c3db8c8a1e upstream.

This was found with a static checker and has not been tested, but it seems
pretty clear that the mutex_lock() was supposed to be mutex_unlock()

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Douglas Schilling Landgraf <dougsland@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: Brandon Philips <brandon@ifup.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>