HID: hidraw: fix window in hidraw_release

HID: hidraw: fix window in hidraw_release

commit cb174681a9ececa6702f114b85bdf82144b6a5af upstream.

There is a window between hidraw_table check and its dereference.
In that window, the device may be unplugged and removed form the
system and we will then dereference NULL.

Lock that place properly so that either we get NULL and jump out or we
can work with real pointer.

[PG: slightly/trivially reworked for backport to 34]

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>