[glib] Prevent an invalid @CARBON_LIBS@ from appearing in the .pc files

[Colin Walters <walters src gnome org>]

commit 9f69534030f963183ac5398889630a641a71409b
Author: Erik van Pienbroek <epienbro fedoraproject org>
Date:   Sat Jun 14 17:10:17 2014 +0200

    Prevent an invalid @CARBON_LIBS@ from appearing in the .pc files
    
    Fixes static linking when using the glib pkgconfig file.
    Regression was introduced in commit 8d037c6 (bz #668152)
    
    https://bugzilla.gnome.org/show_bug.cgi?id=731657

 configure.ac |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 6ede842..6b6ab55 100644
--- a/configure.ac
+++ b/configure.ac
@@ -217,6 +217,8 @@ AS_IF([test "x$glib_have_carbon" = "xyes"], [
   LDFLAGS="$LDFLAGS $CARBON_LIBS"
 ], [CARBON_LIBS=""])
 
+AC_SUBST([CARBON_LIBS])
+
 AS_IF([test "x$glib_have_cocoa" = "xyes"], [
   AC_DEFINE(HAVE_COCOA, 1, [define to 1 if Cocoa is available])
   COCOA_LIBS="-Wl,-framework,Foundation"