[S390] add support for nonquiescing sske

Improve performance of the sske operation by using the nonquiescing
variant if the affected page has no mappings established. On machines
with no support for the new sske variant the mask bit will be ignored.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/mm/rmap.c b/mm/rmap.c
index 92e6757..5f17fad 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -745,7 +745,7 @@
 		if (mapping) {
 			ret = page_mkclean_file(mapping, page);
 			if (page_test_dirty(page)) {
-				page_clear_dirty(page);
+				page_clear_dirty(page, 1);
 				ret = 1;
 			}
 		}
@@ -942,7 +942,7 @@
 	 * containing the swap entry, but page not yet written to swap.
 	 */
 	if ((!PageAnon(page) || PageSwapCache(page)) && page_test_dirty(page)) {
-		page_clear_dirty(page);
+		page_clear_dirty(page, 1);
 		set_page_dirty(page);
 	}
 	/*