net: thunderx: check for failed allocation lmac->dmacs

The allocation of lmac->dmacs is not being checked for allocation
failure. Add the check.

Fixes: 3a34ecfd ("net: thunderx: add MAC address filter tracking for LMAC")
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/cavium/thunder/thunder_bgx.c

@@ -1083,6 +1083,8 @@ static int bgx_lmac_enable(struct bgx *bgx, u8 lmacid)
 	lmac->dmacs_count = (RX_DMAC_COUNT / bgx->lmac_count);
 	lmac->dmacs = kcalloc(lmac->dmacs_count, sizeof(*lmac->dmacs),
 			      GFP_KERNEL);
+	if (!lmac->dmacs)
+		return -ENOMEM;
 
 	/* Enable lmac */
 	bgx_reg_modify(bgx, lmacid, BGX_CMRX_CFG, CMR_EN);