ipv4: move from strlcpy with unused retval to strscpy

Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by a coccinelle script.

Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20220818210219.8467-1-wsa+renesas@sang-engineering.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

net/ipv4/arp.c

@@ -1129,7 +1129,7 @@ static int arp_req_get(struct arpreq *r, struct net_device *dev)
 			r->arp_flags = arp_state_to_flags(neigh);
 			read_unlock_bh(&neigh->lock);
 			r->arp_ha.sa_family = dev->type;
-			strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev));
+			strscpy(r->arp_dev, dev->name, sizeof(r->arp_dev));
 			err = 0;
 		}
 		neigh_release(neigh);