libX11: fix PIE build.

srcpkgs/libX11/template

@@ -1,7 +1,7 @@
 # Template build file for 'libX11'.
 pkgname=libX11
 version=1.6.3
-revision=1
+revision=2
 build_style=gnu-configure
 configure_args="--enable-ipv6 --enable-xlocaledir --without-xmlto
  --disable-secure-rpc --disable-static --enable-malloc0returnsnull"
@@ -22,6 +22,10 @@ if [ "$CROSS_BUILD" ]; then
 	}
 fi
 
+do_configure() {
+	CFLAGS_FOR_BUILD="-fPIC" ./configure ${configure_args}
+}
+
 post_install() {
 	vlicense COPYING
 }