perf tools: do not look at ./config for configuration

In addition to /etc/perfconfig and $HOME/.perfconfig, perf looks for
configuration in the file ./config, imitating git which looks at
$GIT_DIR/config.  If ./config is not a perf configuration file, it
fails, or worse, treats it as a configuration file and changes behavior
in some unexpected way.

"config" is not an unusual name for a file to be lying around and perf
does not have a private directory dedicated for its own use, so let's
just stop looking for configuration in the cwd.  Callers needing
context-sensitive configuration can use the PERF_CONFIG environment
variable.

Requested-by: Christian Ohm <chr.ohm@gmx.net>
Cc: 632923@bugs.debian.org
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Christian Ohm <chr.ohm@gmx.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110805165838.GA7237@elie.gateway.2wire.net
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/config.c

@@ -399,7 +399,6 @@ static int perf_config_global(void)
 int perf_config(config_fn_t fn, void *data)
 {
 	int ret = 0, found = 0;
-	char *repo_config = NULL;
 	const char *home = NULL;
 
 	/* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
@@ -421,12 +420,6 @@ int perf_config(config_fn_t fn, void *data)
 		free(user_config);
 	}
 
-	repo_config = perf_pathdup("config");
-	if (!access(repo_config, R_OK)) {
-		ret += perf_config_from_file(fn, repo_config, data);
-		found += 1;
-	}
-	free(repo_config);
 	if (found == 0)
 		return -1;
 	return ret;