This patch corrects 2 bugs (causes kernel oops) that occur when
unplugging the peripheral whereas nobody has opened it yet :
- do not call usbvision_stop_isoc if usbvision_init_isoc has not been called
- do not call wakeup_interruptible on waitqueues that did not have been
initialized with init_waitqueue_head
Signed-off-by: NThierry MERLE <thierry.merle@free.fr>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>