mm: hwpoison: call shake_page() unconditionally

shake_page() is called before going into core error handling code in
order to ensure that the error page is flushed from lru_cache lists
where pages stay during transferring among LRU lists.

But currently it's not fully functional because when the page is linked
to lru_cache by calling activate_page(), its PageLRU flag is set and
shake_page() is skipped.  The result is to fail error handling with
"still referenced by 1 users" message.

When the page is linked to lru_cache by isolate_lru_page(), its PageLRU
is clear, so that's fine.

This patch makes shake_page() unconditionally called to avoild the
failure.

Fixes: 23a003bfd23ea9ea0b7756b920e51f64b284b468 ("mm/madvise: pass return code of memory_failure() to userspace")
Link: http://lkml.kernel.org/r/20170417055948.GM31394@yexl-desktop
Link: http://lkml.kernel.org/r/1493197841-23986-2-git-send-email-n-horiguchi@ah.jp.nec.com
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Xiaolong Ye <xiaolong.ye@intel.com>
Cc: Chen Gong <gong.chen@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/hwpoison-inject.c b/mm/hwpoison-inject.c
index 9d26fd9..356df05 100644
--- a/mm/hwpoison-inject.c
+++ b/mm/hwpoison-inject.c
@@ -34,8 +34,7 @@
 	if (!hwpoison_filter_enable)
 		goto inject;
 
-	if (!PageLRU(hpage) && !PageHuge(p))
-		shake_page(hpage, 0);
+	shake_page(hpage, 0);
 	/*
 	 * This implies unable to support non-LRU pages.
 	 */