mac80211: Fix one more call to synchronize_rcu in atomic context.

(This set applies OK without the previous one of 4 patches,
 but with some fuzz in the 7th one)

The mesh_path_node_free() does so under hashwlock.

But, this one is called
1. from mesh_path_add() after an old hash is hidden and
   synchronize_rcu() is calld
2. mesh_pathtbl_unregister(), when the module is being
   unloaded and no devices exist to mess with this hash.

So, it seems to me, that simply removing the call is OK.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

net/mac80211/mesh_pathtbl.c

@@ -458,7 +458,6 @@ static void mesh_path_node_free(struct hlist_node *p, bool free_leafs)
 	struct mpath_node *node = hlist_entry(p, struct mpath_node, list);
 	mpath = node->mpath;
 	hlist_del_rcu(p);
-	synchronize_rcu();
 	if (free_leafs)
 		kfree(mpath);
 	kfree(node);