ICMP: Update a variable type

The length of ip_addr can be 4 octet (IPv4 address) if Address Family
Identifier (AFI) is 1 or 16 octets (IPv6 address) if AFI is 2.

Author: fxlb

print-icmp.c

@@ -359,7 +359,7 @@ Interface IP Address Sub-Object
 struct icmp_interface_information_ipaddr_subobject_t {
     nd_uint16_t  afi;
     nd_uint16_t  reserved;
-    nd_uint32_t  ip_addr;
+    nd_byte  ip_addr[1];
 };
 
 /*