net: dsa: sja1105: Unset port from forwarding mask unconditionally on fdb_del

This is a cosmetic patch that simplifies the code by removing a
redundant check. A logical AND-with-zero performed on a zero is still
zero.
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/sja1105/sja1105_main.c

@@ -903,8 +903,8 @@ int sja1105et_fdb_del(struct dsa_switch *ds, int port,
 	 * need to completely evict the FDB entry.
 	 * Otherwise we just write it back.
 	 */
-	if (l2_lookup.destports & BIT(port))
-		l2_lookup.destports &= ~BIT(port);
+	l2_lookup.destports &= ~BIT(port);
+
 	if (l2_lookup.destports)
 		keep = true;
 	else