mm/hwpoison: fix test for a transparent huge page

PageTransHuge() can't guarantee the page is a transparent huge page
since it returns true for both transparent huge and hugetlbfs pages.

This patch fixes it by checking the page is also !hugetlbfs page.

Before patch:

[  121.571128] Injecting memory failure at pfn 23a200
[  121.571141] MCE 0x23a200: huge page recovery: Delayed
[  140.355100] MCE: Memory failure is now running on 0x23a200

After patch:

[   94.290793] Injecting memory failure at pfn 23a000
[   94.290800] MCE 0x23a000: huge page recovery: Delayed
[  105.722303] MCE: Software-unpoisoned page 0x23a000
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memory-failure.c

@@ -1349,7 +1349,7 @@ int unpoison_memory(unsigned long pfn)
 	 * worked by memory_failure() and the page lock is not held yet.
 	 * In such case, we yield to memory_failure() and make unpoison fail.
 	 */
-	if (PageTransHuge(page)) {
+	if (!PageHuge(page) && PageTransHuge(page)) {
 		pr_info("MCE: Memory failure is now running on %#lx\n", pfn);
 			return 0;
 	}