interface: fix checksum flags

Type:fix
Fixes:4208a4c

Change-Id: I7077788cd14f539b06ead5dc65d8411940438bae
Signed-off-by: Florin Coras <fcoras@cisco.com>
Signed-off-by: Dave Wallace <dwallacelf@gmail.com>
diff --git a/src/vnet/interface_output.c b/src/vnet/interface_output.c
index b4832bf..593457c 100644
--- a/src/vnet/interface_output.c
+++ b/src/vnet/interface_output.c
@@ -224,6 +224,9 @@
 	    ip6_tcp_udp_icmp_compute_checksum (vm, b, ip6, &bogus);
 	}
     }
+  b->flags &= ~VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
+  b->flags &= ~VNET_BUFFER_F_OFFLOAD_UDP_CKSUM;
+  b->flags &= ~VNET_BUFFER_F_OFFLOAD_IP_CKSUM;
 }
 
 static_always_inline u16