pagemap: remove wait_on_page_locked_killable()

There is no users of wait_on_page_locked_killable(), remove it.

Link: https://lkml.kernel.org/r/20230815030609.39313-1-wangkefeng.wang@huawei.comSigned-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

include/linux/pagemap.h

@@ -1060,11 +1060,6 @@ static inline void wait_on_page_locked(struct page *page)
 	folio_wait_locked(page_folio(page));
 }
 
-static inline int wait_on_page_locked_killable(struct page *page)
-{
-	return folio_wait_locked_killable(page_folio(page));
-}
-
 void wait_on_page_writeback(struct page *page);
 void folio_wait_writeback(struct folio *folio);
 int folio_wait_writeback_killable(struct folio *folio);