fix build..

ext/overload/config.m4

@@ -1,16 +1,16 @@
 dnl
 dnl $Id$
 dnl
+
 PHP_ARG_ENABLE(overload,whether to enable user-space object overloading support,
 [  --disable-overload      Disable user-space object overloading support.], yes)
 
-
 if test "$PHP_OVERLOAD" != "no"; then
-	AC_CHECK_FILE([Zend/zend_objects.h], [
-		AC_MSG_CHECKING(for overload)
-		AC_MSG_RESULT(not needed with ZendEngine 2)
-	], [
-		AC_DEFINE(HAVE_OVERLOAD, 1, [ ])
-		PHP_NEW_EXTENSION(overload, overload.c, $ext_shared)
-	])
+  if test -f $php_abs_top_srcdir/Zend/zend_objects.h; then
+    AC_MSG_CHECKING(for overload)
+    AC_MSG_RESULT(not needed with ZendEngine 2)
+  else
+    AC_DEFINE(HAVE_OVERLOAD, 1, [ ])
+    PHP_NEW_EXTENSION(overload, overload.c, $ext_shared)
+  fi
 fi