dns: fix compilation with MinGW from commit df69440d05

Avoid 'interface' literal that some MinGW versions define as a macro

Additionally, corrected some very, very minor coding style errors.

lib/asyn-ares.c

@@ -625,15 +625,18 @@ CURLcode Curl_set_dns_servers(struct SessionHandle *data,
 }
 
 CURLcode Curl_set_dns_interface(struct SessionHandle *data,
-                                const char *interface)
+                                const char *interf)
 {
 #if (ARES_VERSION >= 0x010704)
-  if(!interface) interface = "";
-  ares_set_local_dev((ares_channel)data->state.resolver, interface);
+  if(!interf)
+    interf = "";
+
+  ares_set_local_dev((ares_channel)data->state.resolver, interf);
+
   return CURLE_OK;
 #else /* c-ares version too old! */
   (void)data;
-  (void)interface;
+  (void)interf;
   return CURLE_NOT_BUILT_IN;
 #endif
 }
@@ -652,7 +655,9 @@ CURLcode Curl_set_dns_local_ip4(struct SessionHandle *data,
       return CURLE_BAD_FUNCTION_ARGUMENT;
     }
   }
+
   ares_set_local_ip4((ares_channel)data->state.resolver, ntohl(a4));
+
   return CURLE_OK;
 #else /* c-ares version too old! */
   (void)data;
@@ -676,7 +681,9 @@ CURLcode Curl_set_dns_local_ip6(struct SessionHandle *data,
       return CURLE_BAD_FUNCTION_ARGUMENT;
     }
   }
+
   ares_set_local_ip6((ares_channel)data->state.resolver, a6);
+
   return CURLE_OK;
 #else /* c-ares version too old! */
   (void)data;

lib/asyn-thread.c

@@ -636,10 +636,10 @@ CURLcode Curl_set_dns_servers(struct SessionHandle *data,
 }
 
 CURLcode Curl_set_dns_interface(struct SessionHandle *data,
-                                const char *interface)
+                                const char *interf)
 {
   (void)data;
-  (void)interface;
+  (void)interf;
   return CURLE_NOT_BUILT_IN;
 }
 

lib/hostip.h

@@ -205,7 +205,7 @@ CURLcode Curl_set_dns_servers(struct SessionHandle *data, char *servers);
  * outgoing interface to use for DNS requests
  */
 CURLcode Curl_set_dns_interface(struct SessionHandle *data,
-                                const char *interface);
+                                const char *interf);
 
 /*
  * Function provided by the resolver backend to set

lib/hostsyn.c

@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2012, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2013, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -77,10 +77,10 @@ CURLcode Curl_set_dns_servers(struct SessionHandle *data,
  * outgoing interface to use for DNS requests
  */
 CURLcode Curl_set_dns_interface(struct SessionHandle *data,
-                                const char *interface)
+                                const char *interf)
 {
   (void)data;
-  (void)interface;
+  (void)interf;
   return CURLE_NOT_BUILT_IN;
 }