bridge: make `bridge mdb` output consistent with input

bridge -> dev
group -> grp

Signed-off-by: Cong Wang <amwang@redhat.com>
diff --git a/bridge/mdb.c b/bridge/mdb.c
index 6217c5f..81d479b 100644
--- a/bridge/mdb.c
+++ b/bridge/mdb.c
@@ -53,12 +53,12 @@
 	SPRINT_BUF(abuf);
 
 	if (e->addr.proto == htons(ETH_P_IP))
-		fprintf(f, "bridge %s port %s group %s %s\n", ll_index_to_name(ifindex),
+		fprintf(f, "dev %s port %s grp %s %s\n", ll_index_to_name(ifindex),
 			ll_index_to_name(e->ifindex),
 			inet_ntop(AF_INET, &e->addr.u.ip4, abuf, sizeof(abuf)),
 			(e->state & MDB_PERMANENT) ? "permanent" : "temp");
 	else
-		fprintf(f, "bridge %s port %s group %s %s\n", ll_index_to_name(ifindex),
+		fprintf(f, "dev %s port %s grp %s %s\n", ll_index_to_name(ifindex),
 			ll_index_to_name(e->ifindex),
 			inet_ntop(AF_INET6, &e->addr.u.ip6, abuf, sizeof(abuf)),
 			(e->state & MDB_PERMANENT) ? "permanent" : "temp");