selftests: forwarding: mirror_gre_bridge_1q_lag: Enable forwarding

This test relies on routing in the primary traffic path, but neglects to
enable forwarding. Do so.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tools/testing/selftests/net/forwarding/mirror_gre_bridge_1q_lag.sh

@@ -190,6 +190,8 @@ setup_prepare()
 	h4_create
 	switch_create
 
+	forwarding_enable
+
 	trap_install $h3 ingress
 	trap_install $h4 ingress
 }
@@ -201,6 +203,8 @@ cleanup()
 	trap_uninstall $h4 ingress
 	trap_uninstall $h3 ingress
 
+	forwarding_restore
+
 	switch_destroy
 	h4_destroy
 	h3_destroy