perf: Fix perf lock bad rate

Fix the cast made to get the bad rate. It is made in the result
instead of the operands. We need the operands to be cast in double,
otherwise the result will always be zero.
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>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>

tools/perf/builtin-lock.c

@@ -733,8 +733,8 @@ static void print_bad_events(int bad, int total)
 		{ "acquire", "acquired", "contended", "release" };
 
 	pr_info("\n=== output for debug===\n\n");
-	pr_info("bad:%d, total:%d\n", bad, total);
-	pr_info("bad rate:%f\n", (double)(bad / total));
+	pr_info("bad: %d, total: %d\n", bad, total);
+	pr_info("bad rate: %f %%\n", (double)bad / (double)total * 100);
 	pr_info("histogram of events caused bad sequence\n");
 	for (i = 0; i < BROKEN_MAX; i++)
 		pr_info(" %10s: %d\n", name[i], bad_hist[i]);