mm/swapfile: remove needless request_queue NULL pointer check

The request_queue pointer returned from bdev_get_queue() shall never be
NULL, so the null check is unnecessary, just remove it.

Link: https://lkml.kernel.org/r/20210917082111.33923-1-vulab@iscas.ac.cnSigned-off-by: Xu Wang <vulab@iscas.ac.cn>
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/swapfile.c

@@ -3118,7 +3118,7 @@ static bool swap_discardable(struct swap_info_struct *si)
 {
 	struct request_queue *q = bdev_get_queue(si->bdev);
 
-	if (!q || !blk_queue_discard(q))
+	if (!blk_queue_discard(q))
 		return false;
 
 	return true;