netns: fix net_generic array leak

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index b0dc818..f1d07b5 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -96,7 +96,7 @@
 		return;
 	}
 #endif
-
+	kfree(net->gen);
 	kmem_cache_free(net_cachep, net);
 }