perf config: Do not consider an error not to have any perfconfig file

While propagating the errors from perf_config(), which were being
completely ignored, everything stopped working for people without a
~/.perfconfig file, because the perf_config_set__init() was considering
an error not to have a .perfconfig file, duh, fix it by checking the
errno after the failed stat() call.

It should also not return an error when it says it is ignoring the file,
and also a empty file should not return an error either.

Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Taeung Song <[email protected]>
Cc: Wang Nan <[email protected]>
Fixes: 8beeb00 ("perf config: Use new perf_config_set__init() to initialize config set")
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Author: acmel

tools/perf/util/config.c

@@ -646,20 +646,22 @@ static int perf_config_set__init(struct perf_config_set *set)
 			goto out;
 		}
 
-		if (stat(user_config, &st) < 0)
+		if (stat(user_config, &st) < 0) {
+			if (errno == ENOENT)
+				ret = 0;
 			goto out_free;
+		}
+
+		ret = 0;
 
 		if (st.st_uid && (st.st_uid != geteuid())) {
 			warning("File %s not owned by current user or root, "
 				"ignoring it.", user_config);
 			goto out_free;
 		}
 
-		if (!st.st_size)
-			goto out_free;
-
-		ret = perf_config_from_file(collect_config, user_config, set);
-
+		if (st.st_size)
+			ret = perf_config_from_file(collect_config, user_config, set);
 out_free:
 		free(user_config);
 	}