* ext/socket/socket.c (socket_s_list_ip_address): constified.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@21769 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ext/socket/socket.c

@@ -1536,7 +1536,7 @@ socket_s_list_ip_address(VALUE self)
     struct ifconf conf;
     struct ifreq *req;
     VALUE list = Qnil;
-    char *reason = NULL;
+    const char *reason = NULL;
     int save_errno;
 
     fd = socket(AF_INET, SOCK_DGRAM, 0);