pimd: Report del_oif() failure within igmp_source_forward_stop().
diff --git a/pimd/pim_igmpv3.c b/pimd/pim_igmpv3.c
index b95adb6..3baddbf 100644
--- a/pimd/pim_igmpv3.c
+++ b/pimd/pim_igmpv3.c
@@ -388,6 +388,10 @@
   }
 }
 
+/*
+  igmp_source_delete:       stop fowarding, and delete the source
+  igmp_source_forward_stop: stop fowarding, but keep the source
+*/
 void igmp_source_delete(struct igmp_source *source)
 {
   struct igmp_group *group;