Staging: hv: hv_mouse: fix build warning

The trans_id variable (u64) was being incorrectly cast to a unsigned
long * when it should have just been unsigned long.

Fun with pointers, what a fricken mess, we need some real type safety
for these types of fields somehow...

Cc: Hank Janssen <hjanssen@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/hv/hv_mouse.c

@@ -330,7 +330,7 @@ static void MousevscOnSendCompletion(struct hv_device *Device, struct vmpacket_d
 		return;
 	}
 
-	request = (void *)(unsigned long *)Packet->trans_id;
+	request = (void *)(unsigned long)Packet->trans_id;
 
 	if (request == &inputDevice->ProtocolReq) {
 		/* FIXME */