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/file.c b/fs/ocfs2/file.c
index 5d1784a..9d8c3ee 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -296,7 +296,7 @@
 	ocfs2_journal_dirty(handle, bh);
 
 out_commit:
-	ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
+	ocfs2_commit_trans(osb, handle);
 out:
 	return ret;
 }