ocfs2: use 'osb' instead of 'OCFS2_SB()'

We could use 'osb' instead of 'OCFS2_SB()' to make code more elegant.

Link: http://lkml.kernel.org/r/5A702111.7090907@huawei.com
Signed-off-by: Jun Piao <piaojun@huawei.com>
Reviewed-by: Yiwen Jiang <jiangyiwen@huawei.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Cc: Changwei Ge <ge.changwei@h3c.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index ffa4952..e4d54d2 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -423,10 +423,10 @@ static int ocfs2_sync_fs(struct super_block *sb, int wait)
 		ocfs2_schedule_truncate_log_flush(osb, 0);
 	}
 
-	if (jbd2_journal_start_commit(OCFS2_SB(sb)->journal->j_journal,
+	if (jbd2_journal_start_commit(osb->journal->j_journal,
 				      &target)) {
 		if (wait)
-			jbd2_log_wait_commit(OCFS2_SB(sb)->journal->j_journal,
+			jbd2_log_wait_commit(osb->journal->j_journal,
 					     target);
 	}
 	return 0;