perf tools: Fix double word in comments

Delete the repeated word "to" in comments.

Signed-off-by: shaomin Deng <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Author: shaomin Deng

tools/perf/util/events_stats.h

@@ -22,7 +22,7 @@
  *
  * The total_period is needed because by default auto-freq is used, so
  * multiplying nr_events[PERF_EVENT_SAMPLE] by a frequency isn't possible to get
- * the total number of low level events, it is necessary to to sum all struct
+ * the total number of low level events, it is necessary to sum all struct
  * perf_record_sample.period and stash the result in total_period.
  */
 struct events_stats {