Merged in masayuki2009/nuttx.nuttx/fix_rndis (pull request #721)

drivers/usbdev: Fix buffer overrun check in rndis.c

The rndis driver has been working since 13 Nov 2017.
However, I finally found that it depends on network and buffer
configurations. If a receiving TCP packet is devided into smaller
ones based on USB max packet size, this condition check works
correctly.

Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>

Approved-by: GregoryN <gnutt@nuttx.org>

drivers/usbdev/rndis.c

@@ -1249,7 +1249,7 @@ static inline int rndis_recvpacket(FAR struct rndis_dev_s *priv,
 
           /* Check if the received packet exceeds request buffer */
 
-          if ((RNDIS_PACKET_HDR_SIZE + index + copysize) <= CONFIG_NET_ETH_PKTSIZE)
+          if ((index + copysize) <= CONFIG_NET_ETH_PKTSIZE)
             {
               memcpy(&priv->rx_req->req->buf[RNDIS_PACKET_HDR_SIZE + index], reqbuf,
                      copysize);