perf annotate: Simplify header dotted line sizing

No need to use strlen, etc to figure that out, just use the return from
printf(), it will tell how wide the following line needs to be.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20160630082955.GA30921@twins.programming.kicks-ass.net
[ split from a larger patch ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/annotate.c

@@ -1528,7 +1528,7 @@ int symbol__annotate_printf(struct symbol *sym, struct map *map,
 	int more = 0;
 	u64 len;
 	int width = 8;
-	int namelen, evsel_name_len, graph_dotted_len;
+	int graph_dotted_len;
 
 	filename = strdup(dso->long_name);
 	if (!filename)
@@ -1540,17 +1540,14 @@ int symbol__annotate_printf(struct symbol *sym, struct map *map,
 		d_filename = basename(filename);
 
 	len = symbol__size(sym);
-	namelen = strlen(d_filename);
-	evsel_name_len = strlen(evsel_name);
 
 	if (perf_evsel__is_group_event(evsel))
 		width *= evsel->nr_members;
 
-	printf(" %-*.*s|	Source code & Disassembly of %s for %s\n",
+	graph_dotted_len = printf(" %-*.*s|	Source code & Disassembly of %s for %s\n",
 	       width, width, "Percent", d_filename, evsel_name);
 
-	graph_dotted_len = width + namelen + evsel_name_len;
-	printf("-%-*.*s-----------------------------------------\n",
+	printf("%-*.*s----\n",
 	       graph_dotted_len, graph_dotted_len, graph_dotted_line);
 
 	if (verbose)