mm/compaction: remove duplicated VM_BUG_ON_PAGE !PageLocked

The VM_BUG_ON_PAGE(!PageLocked(page), page) is also done in PageMovable.
Remove this explicitly one.

Link: https://lkml.kernel.org/r/20210109081420.46030-1-linmiaohe@huawei.comSigned-off-by: NMiaohe Lin <linmiaohe@huawei.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mm/compaction.c

@@ -137,7 +137,6 @@ EXPORT_SYMBOL(__SetPageMovable);
 
 void __ClearPageMovable(struct page *page)
 {
-	VM_BUG_ON_PAGE(!PageLocked(page), page);
 	VM_BUG_ON_PAGE(!PageMovable(page), page);
 	/*
 	 * Clear registered address_space val with keeping PAGE_MAPPING_MOVABLE