[PATCH net] tools: ynl: fix handling of multiple mcast groups

[Jakub Kicinski <kuba@kernel.org>]

We never increment the group number iterator, so all groups
get recorded into index 0 of the mcast_groups[] array.

As a result YNL can only handle using the last group.
For example using the "netdev" sample on kernel with
page pool commands results in:

  $ ./samples/netdev
  YNL: Multicast group 'mgmt' not found

Most families have only one multicast group, so this hasn't
been noticed. Plus perhaps developers usually test the last
group which would have worked.

Fixes: 86878f14d71a ("tools: ynl: user space helpers")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
CC: nicolas.dichtel@6wind.com
CC: willemb@google.com
---
 tools/net/ynl/lib/ynl.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/net/ynl/lib/ynl.c b/tools/net/ynl/lib/ynl.c
index c2ba72f68028..6bc95f07dc8f 100644
--- a/tools/net/ynl/lib/ynl.c
+++ b/tools/net/ynl/lib/ynl.c
@@ -585,6 +585,7 @@ ynl_get_family_info_mcast(struct ynl_sock *ys, const struct nlattr *mcasts)
 				ys->mcast_groups[i].name[GENL_NAMSIZ - 1] = 0;
 			}
 		}
+		i++;
 	}
 
 	return 0;
-- 
2.43.2