net: macb: Remove dead code

macb_64b_desc is always called when HW_DMA_CAP_64B is defined.
So the return NULL can never be reached. Remove the dead code.
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/cadence/macb_main.c

@@ -165,9 +165,8 @@ static unsigned int macb_adj_dma_desc_idx(struct macb *bp, unsigned int desc_idx
 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
 static struct macb_dma_desc_64 *macb_64b_desc(struct macb *bp, struct macb_dma_desc *desc)
 {
-	if (bp->hw_dma_cap & HW_DMA_CAP_64B)
-		return (struct macb_dma_desc_64 *)((void *)desc + sizeof(struct macb_dma_desc));
-	return NULL;
+	return (struct macb_dma_desc_64 *)((void *)desc
+		+ sizeof(struct macb_dma_desc));
 }
 #endif