mm: compaction: remove duplicate !list_empty(&sublist) check

The list_splice_tail(&sublist, freelist) also do !list_empty(&sublist)
check, so remove the duplicate call.

Link: https://lkml.kernel.org/r/20210609095409.19920-1-liu.xiang@zlingsmart.comSigned-off-by: Liu Xiang <liu.xiang@zlingsmart.com>
Reviewed-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/compaction.c

@@ -1297,8 +1297,7 @@ move_freelist_head(struct list_head *freelist, struct page *freepage)
 
 	if (!list_is_last(freelist, &freepage->lru)) {
 		list_cut_before(&sublist, freelist, &freepage->lru);
-		if (!list_empty(&sublist))
-			list_splice_tail(&sublist, freelist);
+		list_splice_tail(&sublist, freelist);
 	}
 }
 
@@ -1315,8 +1314,7 @@ move_freelist_tail(struct list_head *freelist, struct page *freepage)
 
 	if (!list_is_first(freelist, &freepage->lru)) {
 		list_cut_position(&sublist, freelist, &freepage->lru);
-		if (!list_empty(&sublist))
-			list_splice_tail(&sublist, freelist);
+		list_splice_tail(&sublist, freelist);
 	}
 }