mm: rename page trylock

Converting page lock to new locking bitops requires a change of page flag
operation naming, so we might as well convert it to something nicer
(!TestSetPageLocked_Lock => trylock_page, SetPageLocked => set_page_locked).

This also facilitates lockdeping of page lock.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/migrate.c b/mm/migrate.c
index 153572f..2a80136 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -605,7 +605,7 @@
 	 * establishing additional references. We are the only one
 	 * holding a reference to the new page at this point.
 	 */
-	if (TestSetPageLocked(newpage))
+	if (!trylock_page(newpage))
 		BUG();
 
 	/* Prepare mapping for the new page.*/
@@ -667,7 +667,7 @@
 	BUG_ON(charge);
 
 	rc = -EAGAIN;
-	if (TestSetPageLocked(page)) {
+	if (!trylock_page(page)) {
 		if (!force)
 			goto move_newpage;
 		lock_page(page);