HID: fix non-atomic allocation in hid_input_report

'interrupt' variable can't be used to safely determine whether
we are running in atomic context or not, as we might be called from
during control transfer completion through hid_ctrl() in atomic
context with interrupt == 0.

Reported-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>