Align with other mkdir calls.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <0dd4c8f5-d60e-e564-652f-cd0101f6ee68@web.de>
Message-Id: <20180415230522.24404-5-f4bug@amsat.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>