lib/sbitmap: define swap_lock as raw_spinlock_t

lib/sbitmap: define swap_lock as raw_spinlock_t

When called from sbitmap_queue_get(), sbitmap_deferred_clear() may be run
with preempt disabled. In RT kernel, spin_lock() can sleep, then warning
of "BUG: sleeping function called from invalid context" can be triggered.

Fix it by replacing it with raw_spin_lock.

Cc: Yang Yang <[email protected]>
Fixes: 72d04bdcf3f7 ("sbitmap: fix io hung due to race on sbitmap_word::cleared")
Signed-off-by: Ming Lei <[email protected]>
Reviewed-by: Yang Yang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>