use macros ERRNO, SET_ERRNO(), SOCKERRNO and SET_SOCKERRNO() for errno handling

tests/libtest/test.h

@@ -8,18 +8,17 @@
  * $Id$
  */
 
-#ifdef HAVE_CONFIG_H
 /* Now include the setup.h file from libcurl's private libdir (the source
    version, but that might include "config.h" from the build dir so we need
    both of them in the include path), so that we get good in-depth knowledge
    about the system we're building this on */
 #include "setup.h"
-#endif
 
 #include <curl.h>
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
+#include <errno.h>
 
 #ifdef HAVE_SYS_SOCKET_H
 #include <sys/socket.h>