The .buf_queue() V4L2 driver method is called under
spinlock_irqsave(q->irqlock,...), don't take the lock again inside the
function.
Reported-by: NAntonio Ospite <ospite@studenti.unina.it>
Signed-off-by: NGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>