mm/hugetlb: remove unnecessary VM_BUG_ON_PAGE on putback_active_hugepage()

All callers know they are operating on a hugetlb head page.  So this
VM_BUG_ON_PAGE can not catch anything useful.

Link: https://lkml.kernel.org/r/20210209071151.44731-1-linmiaohe@huawei.comSigned-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/hugetlb.c

@@ -5622,7 +5622,6 @@ bool isolate_huge_page(struct page *page, struct list_head *list)
 
 void putback_active_hugepage(struct page *page)
 {
-	VM_BUG_ON_PAGE(!PageHead(page), page);
 	spin_lock(&hugetlb_lock);
 	set_page_huge_active(page);
 	list_move_tail(&page->lru, &(page_hstate(page))->hugepage_activelist);