staging:r8188eu: remove unused rx_head member of struct recv_frame

Value of rx_head member of struct recv_frame does not used. Remove it.
Signed-off-by: Ivan Safonov <insafonov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8188eu/include/rtw_recv.h

@@ -229,7 +229,6 @@ struct recv_frame {
 	struct adapter  *adapter;
 	struct rx_pkt_attrib attrib;
 	uint  len;
-	u8 *rx_head;
 	u8 *rx_data;
 	u8 *rx_tail;
 	u8 *rx_end;

drivers/staging/rtl8188eu/os_dep/usb_ops_linux.c

@@ -125,7 +125,6 @@ static int recvbuf2recvframe(struct adapter *adapt, struct sk_buff *pskb)
 		if (pkt_copy) {
 			pkt_copy->dev = adapt->pnetdev;
 			precvframe->pkt = pkt_copy;
-			precvframe->rx_head = pkt_copy->data;
 			precvframe->rx_end = pkt_copy->data + alloc_sz;
 			skb_reserve(pkt_copy, 8 - ((size_t)(pkt_copy->data) & 7));/* force pkt_copy->data at 8-byte alignment address */
 			skb_reserve(pkt_copy, shift_sz);/* force ip_hdr at 8-byte alignment address according to shift_sz. */