perf buildid-cache: Show usage with incorrect params

Show usage if no action is specified or unexpected parameter is given.
In other words, be more user friendly.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20150227045030.1999.44006.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-buildid-cache.c

@@ -343,6 +343,11 @@ int cmd_buildid_cache(int argc, const char **argv,
 	argc = parse_options(argc, argv, buildid_cache_options,
 			     buildid_cache_usage, 0);
 
+	if (argc || (!add_name_list_str && !kcore_filename &&
+		     !remove_name_list_str && !purge_name_list_str &&
+		     !missing_filename && !update_name_list_str))
+		usage_with_options(buildid_cache_usage, buildid_cache_options);
+
 	if (missing_filename) {
 		file.path = missing_filename;
 		file.force = force;