hw/usb: pacify xhciwmi.exe warning

xhciwmi.exe is used inside Windows 2022 SVVP tests. This tool called as
'xhciwmi.exe --verify' reports that 'The firmware loaded on this
controller has known bugs and/or compatibility issues'. This is just
a warning but there is no particular sense to ignore it.

This patch just pacifies the tool.

There is a big question whether this change should be put using
machine type mechanics, but at my opinion this would be an overkill.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Tested-by: Pavel Polozov <pavel.polozov@virtuozzo.com>
CC: Yan Vugenfirer <yvugenfi@redhat.com>
CC: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Yan Vugenfirer <yvugenfi@redhat.com>
Message-Id: <20211223095443.130276-1-den@openvz.org>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

hw/usb/hcd-xhci.c

@@ -2523,7 +2523,7 @@ static void xhci_process_commands(XHCIState *xhci)
         case CR_VENDOR_NEC_FIRMWARE_REVISION:
             if (xhci->nec_quirks) {
                 event.type = 48; /* NEC reply */
-                event.length = 0x3025;
+                event.length = 0x3034;
             } else {
                 event.ccode = CC_TRB_ERROR;
             }