perf config: Invert an if statement to reduce nesting in cmd_config()

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1494241650-32210-1-git-send-email-treeze.taeung@gmail.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-config.c

@@ -204,7 +204,11 @@ int cmd_config(int argc, const char **argv)
 		}
 		break;
 	default:
-		if (argc) {
+		if (!argc) {
+			usage_with_options(config_usage, config_options);
+			break;
+		}
+
 		for (i = 0; argv[i]; i++) {
 			char *var, *value;
 			char *arg = strdup(argv[i]);
@@ -227,8 +231,6 @@ int cmd_config(int argc, const char **argv)
 				ret = set_config(set, config_filename, var, value);
 			free(arg);
 		}
-		} else
-			usage_with_options(config_usage, config_options);
 	}
 
 	perf_config_set__delete(set);