test: move include guards up to wrap the whole file

See: https://gcc.gnu.org/onlinedocs/cppinternals/Guard-Macros.html
Signed-off-by: Mike Gelfand <mikedld@mikedld.com>

test/xi2/protocol-common.h

@@ -21,6 +21,9 @@
  *  DEALINGS IN THE SOFTWARE.
  */
 
+#ifndef PROTOCOL_COMMON_H
+#define PROTOCOL_COMMON_H
+
 #ifdef HAVE_DIX_CONFIG_H
 #include <dix-config.h>
 #endif
@@ -34,9 +37,6 @@
 
 #include "tests.h"
 
-#ifndef PROTOCOL_COMMON_H
-#define PROTOCOL_COMMON_H
-
 /* Check default values in a reply */
 #define reply_check_defaults(rep, len, type) \
     { \