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

 reporter_name="Yann Diorcet <diorcet.yann@gmail.com>"

 reporter_url=""

 reporter_comment="Config to build cross-compiler with mingw as kernel type for

 64 bits Windows target"