modules: use gmodule-export

As we want qemu symbols be exported to modules we should use the
gmodule-export-2.0 pkg-config instead of gmodule-2.0.

Cc: Marc-André Lureau <marcandre.lureau@gmail.com>
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Message-id: 20180308085301.8875-2-kraxel@redhat.com

configure

@@ -3352,7 +3352,7 @@ else
 fi
 glib_modules=gthread-2.0
 if test "$modules" = yes; then
-    glib_modules="$glib_modules gmodule-2.0"
+    glib_modules="$glib_modules gmodule-export-2.0"
 fi
 
 # This workaround is required due to a bug in pkg-config file for glib as it