libweston: remove pkgincludedir variable from libweston.pc

Common practise it to provide the includes directly into Cflags, hence
the variable is not needed and we can remove it.

Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Quentin Glidic <sardemff7+git@sardemff7.net>

libweston/libweston.pc.in

@@ -2,11 +2,10 @@ prefix=@prefix@
 exec_prefix=@exec_prefix@
 libdir=@libdir@
 includedir=@includedir@
-pkgincludedir=${includedir}/libweston-@LIBWESTON_ABI_VERSION@
 
 Name: libweston API
 Description: Header files for libweston compositors development
 Version: @WESTON_VERSION@
 Requires.private: wayland-server pixman-1 xkbcommon
-Cflags: -I${pkgincludedir}
+Cflags: -I${includedir}/libweston-@LIBWESTON_ABI_VERSION@
 Libs: -L${libdir} -lweston-@LIBWESTON_ABI_VERSION@