usb: fix usb-host build on windows.

Seems the new API is not available on windows.
Update #ifdefs accordingly.

Fixes: 9f815e83 ("usb: add hostdevice property to usb-host")
Reported-by: NHoward Spoelstra <hsp.cat7@gmail.com>
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Reviewed-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: NHoward Spoelstra <hsp.cat7@gmail.com>
Message-id: 20200624134510.9381-1-kraxel@redhat.com

hw/usb/host-libusb.c

@@ -907,7 +907,7 @@ static int usb_host_open(USBHostDevice *s, libusb_device *dev, int hostfd)
             goto fail;
         }
     } else {
-#if LIBUSB_API_VERSION >= 0x01000107
+#if LIBUSB_API_VERSION >= 0x01000107 && !defined(CONFIG_WIN32)
         trace_usb_host_open_hostfd(hostfd);
 
         rc = libusb_wrap_sys_device(ctx, hostfd, &s->dh);
@@ -1107,7 +1107,7 @@ static void usb_host_realize(USBDevice *udev, Error **errp)
     QTAILQ_INIT(&s->isorings);
     s->hostfd = -1;
 
-#if LIBUSB_API_VERSION >= 0x01000107
+#if LIBUSB_API_VERSION >= 0x01000107 && !defined(CONFIG_WIN32)
     if (s->hostdevice) {
         int fd;
         s->needs_autoscan = false;