The vmstate are valid on win32, just need generate tmp path properly

Signed-off-by: Yonggang Luo <luoyonggang@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20200910103059.987-17-luoyonggang@gmail.com>
[thuth: Make indentation a little bit nicer]
Signed-off-by: Thomas Huth <thuth@redhat.com>