mac80211: Prepare mesh_table_grow to failing copy_node callback.

The mesh_path_node_copy() performs kmalloc() and thus - may fail
(well, it does not now, but I'm fixing this right now). Its caller -
the mesh_table_grow() - isn't prepared for such a trick yet.

This preparation is just flush the new hash and make copy_node()
return an int value.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/mesh.h b/net/mac80211/mesh.h
index 2e161f6..669eafa 100644
--- a/net/mac80211/mesh.h
+++ b/net/mac80211/mesh.h
@@ -109,7 +109,7 @@
 	__u32 hash_rnd;			/* Used for hash generation */
 	atomic_t entries;		/* Up to MAX_MESH_NEIGHBOURS */
 	void (*free_node) (struct hlist_node *p, bool free_leafs);
-	void (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl);
+	int (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl);
 	int size_order;
 	int mean_chain_len;
 };