tg3: Fix fall-through annotations

Replace "fallthru" with a proper "fall through" annotation.

This fix is part of the ongoing efforts to enabling
-Wimplicit-fallthrough

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/tg3.c

@@ -1598,7 +1598,7 @@ static int tg3_mdio_init(struct tg3 *tp)
 			phydev->dev_flags |= PHY_BRCM_EXT_IBND_RX_ENABLE;
 		if (tg3_flag(tp, RGMII_EXT_IBND_TX_EN))
 			phydev->dev_flags |= PHY_BRCM_EXT_IBND_TX_ENABLE;
-		/* fallthru */
+		/* fall through */
 	case PHY_ID_RTL8211C:
 		phydev->interface = PHY_INTERFACE_MODE_RGMII;
 		break;
@@ -2126,7 +2126,7 @@ static int tg3_phy_init(struct tg3 *tp)
 			phy_support_asym_pause(phydev);
 			break;
 		}
-		/* fallthru */
+		/* fall through */
 	case PHY_INTERFACE_MODE_MII:
 		phy_set_max_speed(phydev, SPEED_100);
 		phy_support_asym_pause(phydev);
@@ -5211,7 +5211,7 @@ static int tg3_fiber_aneg_smachine(struct tg3 *tp,
 		if (ap->flags & (MR_AN_ENABLE | MR_RESTART_AN))
 			ap->state = ANEG_STATE_AN_ENABLE;
 
-		/* fallthru */
+		/* fall through */
 	case ANEG_STATE_AN_ENABLE:
 		ap->flags &= ~(MR_AN_COMPLETE | MR_PAGE_RX);
 		if (ap->flags & MR_AN_ENABLE) {
@@ -5241,7 +5241,7 @@ static int tg3_fiber_aneg_smachine(struct tg3 *tp,
 		ret = ANEG_TIMER_ENAB;
 		ap->state = ANEG_STATE_RESTART;
 
-		/* fallthru */
+		/* fall through */
 	case ANEG_STATE_RESTART:
 		delta = ap->cur_time - ap->link_time;
 		if (delta > ANEG_STATE_SETTLE_TIME)
@@ -5284,7 +5284,7 @@ static int tg3_fiber_aneg_smachine(struct tg3 *tp,
 
 		ap->state = ANEG_STATE_ACK_DETECT;
 
-		/* fallthru */
+		/* fall through */
 	case ANEG_STATE_ACK_DETECT:
 		if (ap->ack_match != 0) {
 			if ((ap->rxconfig & ~ANEG_CFG_ACK) ==
@@ -13988,7 +13988,7 @@ static int tg3_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 	case SIOCGMIIPHY:
 		data->phy_id = tp->phy_addr;
 
-		/* fallthru */
+		/* fall through */
 	case SIOCGMIIREG: {
 		u32 mii_regval;