V4L/DVB (9494): anysee: initialize anysee_usb_mutex statically

anysee_usb_mutex is initialized at every time the anysee device is probed.
If the second anysee device is probed while anysee_usb_mutex is locked by
the first anysee device, the mutex is broken.

This patch fixes by initialize anysee_usb_mutex statically rather
than initialize at probe time.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>