perf hists browser: Honour the help line provided by builtin-{top,report}.c

The hists_browser was replacing whatever helpline provided by 'top' or
'report' with a static "Press '?' for help on key bindings", fix it.

Now the message passed by top appears at the bottom of the screen:

"For a higher level overview, try: perf top --sort comm,dso"

As well the message that will be added when the user presses 'f' to
disable the events, something along the lines of "press f again to
re-enable...".

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-dacaja70mbfz3a0yj1n180gx@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/ui/browsers/hists.c

@@ -424,7 +424,7 @@ static void ui_browser__warn_lost_events(struct ui_browser *browser)
 		"Or reduce the sampling frequency.");
 }
 
-static int hist_browser__run(struct hist_browser *browser)
+static int hist_browser__run(struct hist_browser *browser, const char *help)
 {
 	int key;
 	char title[160];
@@ -436,8 +436,7 @@ static int hist_browser__run(struct hist_browser *browser)
 
 	hists__browser_title(browser->hists, hbt, title, sizeof(title));
 
-	if (ui_browser__show(&browser->b, title,
-			     "Press '?' for help on key bindings") < 0)
+	if (ui_browser__show(&browser->b, title, help) < 0)
 		return -1;
 
 	while (1) {
@@ -1773,7 +1772,7 @@ static int perf_evsel__hists_browse(struct perf_evsel *evsel, int nr_events,
 
 		nr_options = 0;
 
-		key = hist_browser__run(browser);
+		key = hist_browser__run(browser, helpline);
 
 		if (browser->he_selection != NULL) {
 			thread = hist_browser__selected_thread(browser);