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/phy/phy.c

@@ -324,9 +324,6 @@ int phy_mii_ioctl(struct phy_device *phydev,
 		break;
 
 	case SIOCSMIIREG:
-		if (!capable(CAP_NET_ADMIN))
-			return -EPERM;
-
 		if (mii_data->phy_id == phydev->addr) {
 			switch(mii_data->reg_num) {
 			case MII_BMCR: