NFSv4: Replace lock_owner->ld_id with an ida based allocator

Again, We're unlikely to ever need more than 2^31 simultaneous lock
owners, so let's replace the custom allocator.

Now that there are no more users, we can also get rid of the custom
allocator code.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index 091b679..b23cb0c 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -81,11 +81,6 @@
 		seqid->flags |= NFS_SEQID_CONFIRMED;
 }
 
-struct nfs_unique_id {
-	struct rb_node rb_node;
-	__u64 id;
-};
-
 /*
  * NFS4 state_owners and lock_owners are simply labels for ordered
  * sequences of RPC calls. Their sole purpose is to provide once-only
@@ -145,9 +140,9 @@
 	struct nfs4_state *	ls_state;	/* Pointer to open state */
 #define NFS_LOCK_INITIALIZED 1
 	int			ls_flags;
+	int			ls_id;
 	struct nfs_seqid_counter	ls_seqid;
 	struct rpc_sequence	ls_sequence;
-	struct nfs_unique_id	ls_id;
 	nfs4_stateid		ls_stateid;
 	atomic_t		ls_count;
 	struct nfs4_lock_owner	ls_owner;