Staging: rt*: fix wait_queue_head_t declaration on stack

othwerwise lockdep complains:
"INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator."

Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>