Coverage data suggests that the unlikely case of receiving data while
the receive handler is running may not be that unlikely.
Coverage data after running iperf for a while:
    91320:  891:	work_done = bp->macbgem_ops.mog_rx(bp, budget);
    91320:  892:	if (work_done < budget) {
     2362:  893:		napi_complete(napi);
        -:  894:
        -:  895:		/* Packets received while interrupts were disabled */
     4724:  896:		status = macb_readl(bp, RSR);
     2362:  897:		if (unlikely(status)) {
      762:  898:			if (bp->caps & MACB_CAPS_ISR_CLEAR_ON_WRITE)
      762:  899:				macb_writel(bp, ISR, MACB_BIT(RCOMP));
        -:  900:			napi_reschedule(napi);
        -:  901:		} else {
     1600:  902:			macb_writel(bp, IER, MACB_RX_INT_FLAGS);
        -:  903:		}
        -:  904:	}
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>