net: dsa: setup master ethtool unconditionally

When a DSA switch tree is meant to be applied, it already has a CPU
port. Thus remove the condition of dst->cpu_dp.

Moreover, the next lines access dst->cpu_dp unconditionally.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/dsa/dsa2.c

@@ -433,11 +433,9 @@ static int dsa_dst_apply(struct dsa_switch_tree *dst)
 			return err;
 	}
 
-	if (dst->cpu_dp) {
 	err = dsa_cpu_port_ethtool_setup(dst->cpu_dp);
 	if (err)
 		return err;
-	}
 
 	/* If we use a tagging format that doesn't have an ethertype
 	 * field, make sure that all packets from this point on get
@@ -474,10 +472,8 @@ static void dsa_dst_unapply(struct dsa_switch_tree *dst)
 		dsa_ds_unapply(dst, ds);
 	}
 
-	if (dst->cpu_dp) {
 	dsa_cpu_port_ethtool_restore(dst->cpu_dp);
 	dst->cpu_dp = NULL;
-	}
 
 	pr_info("DSA: tree %d unapplied\n", dst->tree);
 	dst->applied = false;