perf hists: Replace perf_evsel arg perf_hpp_fmt's width callback

Replacing perf_evsel arg perf_hpp_fmt's width callback with hists
object.

This will be helpful in future for non evsel related hist browsers.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1465928361-2442-11-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index b75ea77..7f628f9 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -1056,7 +1056,7 @@
 
 static int hpp__width(struct perf_hpp_fmt *fmt,
 		      struct perf_hpp *hpp __maybe_unused,
-		      struct perf_evsel *evsel __maybe_unused)
+		      struct hists *hists __maybe_unused)
 {
 	struct diff_hpp_fmt *dfmt =
 		container_of(fmt, struct diff_hpp_fmt, fmt);