perf tools: Add name field into perf_hpp_fmt

It makes the code a bit simpler and easier to debug IMHO.

I guess it can also remove similar code in perf diff, but let's keep
it for a future work. :)

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1406785662-5534-7-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/ui/gtk/hists.c

@@ -207,10 +207,8 @@ static void perf_gtk__show_hists(GtkWidget *window, struct hists *hists,
 		if (perf_hpp__is_sort_entry(fmt))
 			sym_col = col_idx;
 
-		fmt->header(fmt, &hpp, hists_to_evsel(hists));
-
 		gtk_tree_view_insert_column_with_attributes(GTK_TREE_VIEW(view),
-							    -1, ltrim(s),
+							    -1, fmt->name,
 							    renderer, "markup",
 							    col_idx++, NULL);
 	}