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/fs/splice.c b/fs/splice.c
index b30311b..1bbc6f4 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -371,7 +371,7 @@
 			 * for an in-flight io page
 			 */
 			if (flags & SPLICE_F_NONBLOCK) {
-				if (TestSetPageLocked(page)) {
+				if (!trylock_page(page)) {
 					error = -EAGAIN;
 					break;
 				}