scripts: unquoted variable reference in glibc-eglibc.sh-common

Signed-off-by: Daniel Price <daniel.price@gmail.com>
Message-Id: <12f092a95a94bcf76912.1353367250@redfish.dssd.com>
Patchwork-Id: 200215

# Compute Alpha-specific values

CT_DoArchTupleValues () {

    # The architecture part of the tuple:

    CT_TARGET_ARCH="${CT_ARCH}${CT_ARCH_ALPHA_VARIANT}"

}