selftests: net: udpgso_bench_rx/tx: Stop when wrong CLI args are provided

Leaving unrecognized arguments buried in the output, can easily hide a
CLI/script typo. Avoid this by exiting when wrong arguments are provided to
the udpgso_bench test programs.

Fixes: 3a687bef14 ("selftests: udp gso benchmark")
Signed-off-by: Andrei Gherzan <andrei.gherzan@canonical.com>
Cc: Willem de Bruijn <willemb@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20230201001612.515730-2-andrei.gherzan@canonical.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

tools/testing/selftests/net/udpgso_bench_rx.c

@@ -336,6 +336,8 @@ static void parse_opts(int argc, char **argv)
 			cfg_verify = true;
 			cfg_read_all = true;
 			break;
+		default:
+			exit(1);
 		}
 	}
 

tools/testing/selftests/net/udpgso_bench_tx.c

@@ -490,6 +490,8 @@ static void parse_opts(int argc, char **argv)
 		case 'z':
 			cfg_zerocopy = true;
 			break;
+		default:
+			exit(1);
 		}
 	}