net: ethernet: aquantia: Fixed incorrect buff->len calculation.

rxd_wb->pkt_len is the total length of the packet.
If we received a large packet (with length > AQ_CFG_RX_FRAME_MAX) then we
will get multiple buffers. We need to fix the length of the last buffer.
Signed-off-by: Pavel Belous <pavel.belous@aquantia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/aquantia/atlantic/hw_atl/hw_atl_a0.c

@@ -659,8 +659,8 @@ static int hw_atl_a0_hw_ring_rx_receive(struct aq_hw_s *self,
 			}
 
 			if (HW_ATL_A0_RXD_WB_STAT2_EOP & rxd_wb->status) {
-				buff->len = (rxd_wb->pkt_len &
-						(AQ_CFG_RX_FRAME_MAX - 1U));
+				buff->len = rxd_wb->pkt_len %
+					AQ_CFG_RX_FRAME_MAX;
 				buff->len = buff->len ?
 					buff->len : AQ_CFG_RX_FRAME_MAX;
 				buff->next = 0U;

drivers/net/ethernet/aquantia/atlantic/hw_atl/hw_atl_b0.c

@@ -673,8 +673,8 @@ static int hw_atl_b0_hw_ring_rx_receive(struct aq_hw_s *self,
 			}
 
 			if (HW_ATL_B0_RXD_WB_STAT2_EOP & rxd_wb->status) {
-				buff->len = (rxd_wb->pkt_len &
-						(AQ_CFG_RX_FRAME_MAX - 1U));
+				buff->len = rxd_wb->pkt_len %
+					AQ_CFG_RX_FRAME_MAX;
 				buff->len = buff->len ?
 					buff->len : AQ_CFG_RX_FRAME_MAX;
 				buff->next = 0U;