perf: Fix callchain hit bad cast on ascii display

ipchain__fprintf_graph() casts the number of hits in a branch as an
int, which means we lose its highests bits.

This results in meaningless number of callchain hits in perf.data
that have a high number of hits recorded, typically those that have
callchain branches hits appearing more than INT_MAX. This happens
easily as those are pondered by the event period.
Reported-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>

tools/perf/util/hist.c

@@ -356,7 +356,7 @@ static size_t ipchain__fprintf_graph_line(FILE *fp, int depth, int depth_mask,
 
 static size_t ipchain__fprintf_graph(FILE *fp, struct callchain_list *chain,
 				     int depth, int depth_mask, int period,
-				     u64 total_samples, int hits,
+				     u64 total_samples, u64 hits,
 				     int left_margin)
 {
 	int i;