meta-google: gbmc-bridge: Fix nftable rule set

Seems that nftable cannot jump to a chain that doesn't in its own file.

Change-Id: I4d8c0cd804afddaae7ae5e94b5db1266b149fb55
Signed-off-by: Yuxiao Zhang <yuxiaozhang@google.com>
diff --git a/meta-google/recipes-google/networking/gbmc-bridge/50-gbmc-br.rules b/meta-google/recipes-google/networking/gbmc-bridge/50-gbmc-br.rules
index 5bc58f0..72dde39 100644
--- a/meta-google/recipes-google/networking/gbmc-bridge/50-gbmc-br.rules
+++ b/meta-google/recipes-google/networking/gbmc-bridge/50-gbmc-br.rules
@@ -12,8 +12,8 @@
   chain gbmc_br_input {
     type filter hook input priority 0; policy drop;
     iifname != gbmcbr accept
+    mark 0xff drop
     ct state established accept
-    jump gbmc_br_redir_input
     jump gbmc_br_int_input
     jump gbmc_br_pub_input
     reject
@@ -35,3 +35,4 @@
     ip6 nexthdr icmpv6 accept
   }
 }
+