Set AI_CANONNAME flag in socket_addrinfo test

Musl always populates ai_canonname. Set the flag to avoid output
discrepancies.

Author: nikic

ext/sockets/tests/socket_addrinfo_explain.phpt

@@ -10,11 +10,12 @@ if (!extension_loaded('sockets')) {
 $addrinfo = socket_addrinfo_lookup('127.0.0.1', 2000, array(
     'ai_family' => AF_INET,
     'ai_socktype' => SOCK_DGRAM,
+    'ai_flags' => AI_CANONNAME,
 ));
 var_dump(socket_addrinfo_explain($addrinfo[0]));
 echo "Done";
 --EXPECTF--
-array(5) {
+array(6) {
   ["ai_flags"]=>
   int(%d)
   ["ai_family"]=>
@@ -23,6 +24,8 @@ array(5) {
   int(2)
   ["ai_protocol"]=>
   int(%d)
+  ["ai_canonname"]=>
+  string(9) "127.0.0.1"
   ["ai_addr"]=>
   array(2) {
     ["sin_port"]=>