perf tools: Fix assertion failure on dynamic entry

The dynamic entry is created for each field in a tracepoint event.
Since they have no fixed hpp format index, it should skip when
perf_hpp__reset_width() is called.

This caused following assertion failure..

  $ perf record -e sched:sched_switch -a sleep 1

  $ perf report -s comm,next_pid --stdio
  perf: ui/hist.c:651: perf_hpp__reset_width:
    Assertion `!(fmt->idx >= PERF_HPP__MAX_INDEX)' failed.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1456064558-13086-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/ui/hist.c

@@ -645,6 +645,9 @@ void perf_hpp__reset_width(struct perf_hpp_fmt *fmt, struct hists *hists)
 	if (perf_hpp__is_sort_entry(fmt))
 		return perf_hpp__reset_sort_width(fmt, hists);
 
+	if (perf_hpp__is_dynamic_entry(fmt))
+		return;
+
 	BUG_ON(fmt->idx >= PERF_HPP__MAX_INDEX);
 
 	switch (fmt->idx) {