JFS: commit_mutex cleanups

I look at code, and see that
1)locks wasn't release in the opposite order in which they were taken
2)in jfs_rename we lock new_ip, and in "error path" we didn't unlock it
3)I see strange expression: "! !"

May be this worth to fix?

Signed-off-by: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
diff --git a/fs/jfs/jfs_txnmgr.c b/fs/jfs/jfs_txnmgr.c
index ac3d669..49618dd 100644
--- a/fs/jfs/jfs_txnmgr.c
+++ b/fs/jfs/jfs_txnmgr.c
@@ -2944,7 +2944,7 @@
 				 * Inode is being freed
 				 */
 				list_del_init(&jfs_ip->anon_inode_list);
-			} else if (! !mutex_trylock(&jfs_ip->commit_mutex)) {
+			} else if (mutex_trylock(&jfs_ip->commit_mutex)) {
 				/*
 				 * inode will be removed from anonymous list
 				 * when it is committed