test_icmp_reply_size: fix for ipv4-only case

Closes: #292
Approved by: whitequark

.travis.yml

@@ -17,6 +17,8 @@ matrix:
       env: FEATURES='std phy-tap_interface proto-ipv6 socket-udp' MODE='test'
     - rust: nightly
       env: FEATURES='std proto-ipv4 proto-igmp socket-raw' MODE='test'
+    - rust: nightly
+      env: FEATURES='std proto-ipv4 socket-udp socket-tcp' MODE='test'
     - rust: nightly
       env: FEATURES='std proto-ipv6 socket-udp' MODE='test'
     - rust: nightly

src/iface/ethernet.rs

@@ -2195,7 +2195,7 @@ mod test {
             dst_addr: src_addr,
             protocol: IpProtocol::Icmp,
             hop_limit: 64,
-            payload_len: expected_icmpv4_repr.buffer_len()
+            payload_len: expected_icmp_repr.buffer_len()
         };
 
         // The expected packet does not exceed the IPV4_MIN_MTU