perf help: Change 'usage' to 'Usage' for consistency

Capitalize 'usage' to make it consistent with all the other 'Usage' in
the codes, e.g., usage_builtin.

Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ramkumar Ramachandra <artagnon@gmail.com>
Cc: Sriram Raghunathan <sriram.r@nokia.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1444894792-2338-3-git-send-email-yunlong.song@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/builtin-help.c b/tools/perf/builtin-help.c
index 36486ea..a7d588b 100644
--- a/tools/perf/builtin-help.c
+++ b/tools/perf/builtin-help.c
@@ -463,7 +463,7 @@
 			builtin_help_subcommands, builtin_help_usage, 0);
 
 	if (show_all) {
-		printf("\n usage: %s\n\n", perf_usage_string);
+		printf("\n Usage: %s\n\n", perf_usage_string);
 		list_commands("perf commands", &main_cmds, &other_cmds);
 		printf(" %s\n\n", perf_more_info_string);
 		return 0;