qga: Fix handle fd leak in acquire_privilege()

token should be closed in all conditions.
So move CloseHandle(token) to "out" branch.

Signed-off-by: Wang Rui <moon.wangrui@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
