ocfs2: release the buffer head in ocfs2_do_truncate.

In ocfs2_do_truncate, we forget to release last_eb_bh which
will cause memleak. So call brelse in the end.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c
index f9a3e89..ab513dd 100644
--- a/fs/ocfs2/alloc.c
+++ b/fs/ocfs2/alloc.c
@@ -6851,7 +6851,7 @@
 	}
 	status = 0;
 bail:
-
+	brelse(last_eb_bh);
 	mlog_exit(status);
 	return status;
 }