[intel] Report receive overruns via network device errors

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/drivers/net/intel.c

 	if ( icr & INTEL_IRQ_TXDW )
 		intel_poll_tx ( netdev );
 
-	/* Poll for RX completionsm, if applicable */
+	/* Poll for RX completions, if applicable */
 	if ( icr & INTEL_IRQ_RXT0 )
 		intel_poll_rx ( netdev );
 
+	/* Report receive overruns */
+	if ( icr & INTEL_IRQ_RXO )
+		netdev_rx_err ( netdev, NULL, -ENOBUFS );
+
 	/* Check link state, if applicable */
 	if ( icr & INTEL_IRQ_LSC )
 		intel_check_link ( netdev );

src/drivers/net/intel.h

 #define INTEL_IRQ_TXDW		0x00000001UL	/**< Transmit descriptor done */
 #define INTEL_IRQ_LSC		0x00000004UL	/**< Link status change */
 #define INTEL_IRQ_RXT0		0x00000080UL	/**< Receive timer */
+#define INTEL_IRQ_RXO		0x00000400UL	/**< Receive overrun */
 
 /** Interrupt Mask Set/Read Register */
 #define INTEL_IMS 0x000d0UL