nterface-ip: remove superfluous iface check in interface_ip_set_enabled()

No need to check iface pointer in interface_ip_set_enabled as the
interface is always set by the function __interface_ip_init().
Reported by Coverity in CID 1330437

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>

interface-ip.c

@@ -1442,7 +1442,7 @@ void interface_ip_set_enabled(struct interface_ip_settings *ip, bool enabled)
 			if (!strcmp(a->name, ip->iface->name))
 				interface_set_prefix_address(a, c, ip->iface, enabled);
 
-	if (ip->iface && ip->iface->policy_rules_set != enabled &&
+	if (ip->iface->policy_rules_set != enabled &&
 	    ip->iface->l3_dev.dev) {
 		set_ip_lo_policy(enabled, true, ip->iface);
 		set_ip_lo_policy(enabled, false, ip->iface);