netdev: Remove redundant checks for CAP_NET_ADMIN in MDIO implementations

dev_ioctl() already checks capable(CAP_NET_ADMIN) before calling the
driver's implementation of MDIO ioctls.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/igb/igb_main.c

@@ -4914,8 +4914,6 @@ static int igb_mii_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd)
 		data->phy_id = adapter->hw.phy.addr;
 		break;
 	case SIOCGMIIREG:
-		if (!capable(CAP_NET_ADMIN))
-			return -EPERM;
 		if (igb_read_phy_reg(&adapter->hw, data->reg_num & 0x1F,
 		                     &data->val_out))
 			return -EIO;