jbd2: save some atomic ops in __JI_COMMIT_RUNNING handling

Currently we used atomic bit operations to manipulate
__JI_COMMIT_RUNNING bit. However this is unnecessary as i_flags are
always written and read under j_list_lock. So just change the operations
to standard bit operations.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index defa962..7bf1683 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -2587,7 +2587,7 @@
 restart:
 	spin_lock(&journal->j_list_lock);
 	/* Is commit writing out inode - we have to wait */
-	if (test_bit(__JI_COMMIT_RUNNING, &jinode->i_flags)) {
+	if (jinode->i_flags & JI_COMMIT_RUNNING) {
 		wait_queue_head_t *wq;
 		DEFINE_WAIT_BIT(wait, &jinode->i_flags, __JI_COMMIT_RUNNING);
 		wq = bit_waitqueue(&jinode->i_flags, __JI_COMMIT_RUNNING);