perf lock: Limit bad rate precision

Two decimal precision should be enough for this.
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1378693159-8747-7-git-send-email-davidlohr@hp.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-lock.c

@@ -686,7 +686,7 @@ static void print_bad_events(int bad, int total)
 
 	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 / (double)total * 100);
+	pr_info("bad rate: %.2f %%\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]);