net: tulip: de4x5: mark expected switch fall-throughs

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Addresses-Coverity-ID: 114784 ("Missing break in switch")
Addresses-Coverity-ID: 114785 ("Missing break in switch")
Addresses-Coverity-ID: 114786 ("Missing break in switch")
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/dec/tulip/de4x5.c

@@ -3204,6 +3204,8 @@ srom_map_media(struct net_device *dev)
       case SROM_10BASETF:
 	if (!lp->params.fdx) return -1;
 	lp->fdx = true;
+	/* fall through */
+
       case SROM_10BASET:
 	if (lp->params.fdx && !lp->fdx) return -1;
 	if ((lp->chipset == DC21140) || ((lp->chipset & ~0x00ff) == DC2114x)) {
@@ -3224,6 +3226,8 @@ srom_map_media(struct net_device *dev)
       case SROM_100BASETF:
         if (!lp->params.fdx) return -1;
 	lp->fdx = true;
+	/* fall through */
+
       case SROM_100BASET:
 	if (lp->params.fdx && !lp->fdx) return -1;
 	lp->media = _100Mb;
@@ -3236,6 +3240,8 @@ srom_map_media(struct net_device *dev)
       case SROM_100BASEFF:
 	if (!lp->params.fdx) return -1;
 	lp->fdx = true;
+	/* fall through */
+
       case SROM_100BASEF:
 	if (lp->params.fdx && !lp->fdx) return -1;
 	lp->media = _100Mb;