newlib: fix extract process for custom version

newlib: fix extract process for custom version

If the user specifies the use of a custom newlib version, the logic in the
extract function was reversed, so this step would fail.

Signed-off-by: Trevor Woerner <trevor.woerner@linaro.org>
[yann.morin.1998@free.fr: keep leading indentation]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Message-Id: <c727adf1b7bd2c1e891d.1393353347@openSUSE-i7>
Patchwork-Id: 324060

#!/bin/sh

call_to=@@DEFAULT_LD@@

case "${CTNG_LD_IS}" in

    bfd)    call_to=bfd;;

    gold)   call_to=gold;;

esac

exec "${0}.${call_to}" "$@"

exit $?