The pwc driver is defficient in locking, which can trigger an oops
when disconnecting.
Signed-off-by: NOliver Neukum <oneukum@suse.de>
CC: Luc Saillard <luc@saillard.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>