x86-64, NUMA: Remove unused variable

In case !CONFIG_ACPI_NUMA and !CONFIG_AMD_NUMA gcc emits a warning
about the unused variable ret.

As that variable is in fact not needed I choose to remove it.

Signed-off-by: Florian Mickler <florian@mickler.org>
LKML-Reference: <1301843624-22364-1-git-send-email-florian@mickler.org>
Signed-off-by: Tejun Heo <tj@kernel.org>