perf TUI: Make 'space' be an alias to 'PgDn'

Just like if one is using the stdio based pager, or more/less, for that
matter.
Suggested-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/newt.c

@@ -383,6 +383,7 @@ static int ui_browser__run(struct ui_browser *self, const char *title,
 	newtFormAddHotKey(self->form, NEWT_KEY_DOWN);
 	newtFormAddHotKey(self->form, NEWT_KEY_PGUP);
 	newtFormAddHotKey(self->form, NEWT_KEY_PGDN);
+	newtFormAddHotKey(self->form, ' ');
 	newtFormAddHotKey(self->form, NEWT_KEY_HOME);
 	newtFormAddHotKey(self->form, NEWT_KEY_END);
 
@@ -419,6 +420,7 @@ static int ui_browser__run(struct ui_browser *self, const char *title,
 			}
 			break;
 		case NEWT_KEY_PGDN:
+		case ' ':
 			if (self->first_visible_entry_idx + self->height > self->nr_entries - 1)
 				break;