Use native pkg-config when looking for gtk-doc.

Upstream-Status: Inappropriate
Signed-off-by: Ross Burton <ross.burton@intel.com>

diff --git a/gtk-doc.m4 b/gtk-doc.m4
index 3675543..94881ae 100644
--- a/gtk-doc.m4
+++ b/gtk-doc.m4
@@ -1,6 +1,6 @@
 dnl -*- mode: autoconf -*-

-# serial 2
+# serial 2.1

 dnl Usage:
 dnl   GTK_DOC_CHECK([minimum-gtk-doc-version])
@@ -10,11 +10,16 @@ AC_DEFUN([GTK_DOC_CHECK],
   AC_BEFORE([AC_PROG_LIBTOOL],[$0])dnl setup libtool first
   AC_BEFORE([AM_PROG_LIBTOOL],[$0])dnl setup libtool first

+  gtkdoc_pkgconfig_save=$PKG_CONFIG
+  PKG_CONFIG=pkg-config-native
+
   ifelse([$1],[],[gtk_doc_requires="gtk-doc"],[gtk_doc_requires="gtk-doc >= $1"])
   AC_MSG_CHECKING([for gtk-doc])
   PKG_CHECK_EXISTS([$gtk_doc_requires],[have_gtk_doc=yes],[have_gtk_doc=no])
   AC_MSG_RESULT($have_gtk_doc)

+  PKG_CONFIG=$gtkdoc_pkgconfig_save
+
   if test "$have_gtk_doc" = "no"; then
       AC_MSG_WARN([
   You will not be able to create source packages with 'make dist'