sd-dhcp-server: drop unnecessary buffer duplication

The block try to find and remove the existing static lease which matches
the provided client ID, and the provided client ID will not be stored
anywhere. Hence, it is not necessary to duplicate it.

src/libsystemd-network/sd-dhcp-server.c

@@ -1536,18 +1536,13 @@ int sd_dhcp_server_set_static_lease(
         assert_return(!sd_dhcp_server_is_running(server), -EBUSY);
 
         /* Static lease with an empty or omitted address is a valid entry,
-        * the server removes any static lease with the specified mac address. */
+         * the server removes any static lease with the specified mac address. */
         if (!address || address->s_addr == 0) {
-                _cleanup_free_ void *data = NULL;
                 DHCPClientId c;
 
-                data = memdup(client_id, client_id_size);
-                if (!data)
-                        return -ENOMEM;
-
                 c = (DHCPClientId) {
                         .length = client_id_size,
-                        .data = data,
+                        .data = client_id,
                 };
 
                 dhcp_lease_free(hashmap_remove(server->static_leases_by_client_id, &c));