[gcr] Search for valgrind headers in build/ directory

[Laurent Bigonville <lbigon src gnome org>]

commit 6dd3ea96fb918e663ff30c71fb5dc7f60f96a6e5
Author: Laurent Bigonville <bigon bigon be>
Date:   Mon Dec 16 23:38:40 2013 +0100

    Search for valgrind headers in build/ directory
    
    This is fixing the build failure introduced by the previous patch if the
    valgrind headers are not installed in the system path.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=702648

 configure.ac |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index c69423f..2f348d8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -365,7 +365,10 @@ AC_SUBST(VALGRIND_RUN)
 
 # Build valgrind support into code
 if test "$enable_valgrind" = "yes"; then
+       CPPFLAGS_saved="$CPPFLAGS"
+       CPPFLAGS="$CPPFLAGS -I${srcdir}/build"
        AC_CHECK_HEADER([valgrind/valgrind.h], have_valgrind=yes, have_valgrind=no)
+       CPPFLAGS="$CPPFLAGS_saved"
        if test "$have_valgrind" = "no"; then
                AC_MSG_ERROR(The valgrind headers are missing)
        fi