net: shell: dns: use int type for %.*s format specifier

The `%.*s` format specifier expects an int so cast the size_t parameter
to int.

Fixes an issue spotted in CI for:

    west twister -p native_sim/native/64 -s sample.net.dns_resolve.mdns

Signed-off-by: Benjamin Cabé <[email protected]>

Author: kartben

subsys/net/lib/shell/dns.c

@@ -65,7 +65,7 @@ static void dns_result_cb(enum dns_resolve_status status,
 					 info->ai_srv.priority,
 					 info->ai_srv.weight,
 					 info->ai_srv.port,
-					 info->ai_srv.targetlen,
+					 (int)info->ai_srv.targetlen,
 					 info->ai_srv.target);
 				break;
 			}