usb: drop unused USBNetState.inpkt field

Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>
Reviewed-by: NGerd Hoffmann <kraxel@redhat.com>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

hw/usb/dev-network.c

@@ -637,7 +637,6 @@ typedef struct USBNetState {
     unsigned int out_ptr;
     uint8_t out_buf[2048];
 
-    USBPacket *inpkt;
     unsigned int in_ptr, in_len;
     uint8_t in_buf[2048];