qemu-option: Replace pointless use of g_malloc0() by g_malloc() get_opt_value() takes a write-only buffer, so zeroing it is pointless. We don't do it elsewhere, either. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Gonglei <arei.gonglei@huawei.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>