rtnetlink: Drop unnecessary return value from ndo_dflt_fdb_del

This change cleans up ndo_dflt_fdb_del to drop the ENOTSUPP return value since
that isn't actually returned anywhere in the code.  As a result we are able to
drop a few lines by just defaulting this to -EINVAL.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/core/rtnetlink.c

@@ -2392,22 +2392,20 @@ int ndo_dflt_fdb_del(struct ndmsg *ndm,
 		     struct net_device *dev,
 		     const unsigned char *addr)
 {
-	int err = -EOPNOTSUPP;
+	int err = -EINVAL;
 
 	/* If aging addresses are supported device will need to
 	 * implement its own handler for this.
 	 */
 	if (!(ndm->ndm_state & NUD_PERMANENT)) {
 		pr_info("%s: FDB only supports static addresses\n", dev->name);
-		return -EINVAL;
+		return err;
 	}
 
 	if (is_unicast_ether_addr(addr) || is_link_local_ether_addr(addr))
 		err = dev_uc_del(dev, addr);
 	else if (is_multicast_ether_addr(addr))
 		err = dev_mc_del(dev, addr);
-	else
-		err = -EINVAL;
 
 	return err;
 }