perf stat: Factor out body of event handling loop for fork case

Factor out body of event handling loop for fork case reusing
handle_interval() function.
Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/a8ae3f8d-a30e-fd40-998a-f5ca3e98cd45@linux.intel.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-stat.c

@@ -792,10 +792,7 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
 		if (interval || timeout) {
 			while (!waitpid(child_pid, &status, WNOHANG)) {
 				nanosleep(&ts, NULL);
-				if (timeout)
-					break;
-				process_interval();
-				if (interval_count && !(--times))
+				if (timeout || handle_interval(interval, &times))
 					break;
 			}
 		}