Added call to env-update after installing gcc libraries into a board root.

This allows ld.so.cache to be properly regenerated.

BUG=chromium-os:22324
TEST=./cbuildbot tegra2_kaen-release. Run desktopui_FontConfig and check it succeeds.

Change-Id: I546c4ef1e5d61117d416f681cb5e75e884600ed2
Reviewed-on: https://gerrit.chromium.org/gerrit/11063
Reviewed-by: Grant Grundler <grundler@chromium.org>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: David James <davidjames@chromium.org>
Commit-Ready: Raymes Khoury <raymes@chromium.org>
Tested-by: Raymes Khoury <raymes@chromium.org>
diff --git a/toolchain_utils.sh b/toolchain_utils.sh
index 1f344b2..872c668 100755
--- a/toolchain_utils.sh
+++ b/toolchain_utils.sh
@@ -77,6 +77,7 @@
   fi
   copy_gcc_libs_helper $target_location $libgcc_file
   copy_gcc_libs_helper $target_location $libstdcxx_file
+  sudo ROOT="$target_location" env-update
   return 0
 }