[PKT_SCHED]: Return ENOENT if action module is unavailable

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index f9d1d78..9b2e397 100644
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -305,6 +305,7 @@
 			goto err_mod;
 		}
 #endif
+		*err = -ENOENT;
 		goto err_out;
 	}