ocfs2: Fix error return in ocfs2_write_cluster()

A typo caused ocfs2_write_cluster() to return 0 in some error cases.
Fix it.

Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index b2c52b3..25aced3 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -1301,7 +1301,7 @@
 		if (tmpret) {
 			mlog_errno(tmpret);
 			if (ret == 0)
-				tmpret = ret;
+				ret = tmpret;
 		}
 	}