perf tools: Do not auto-remove Children column if --fields given

Depending on the configuration perf inserts/removes the Children
column in the output automatically.  But it might not be what user
wants if [s]he give --fields option explicitly.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Rodrigo Campos <rodrigo@sdfg.com.ar>
Cc: Arun Sharma <asharma@fb.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1401335910-16832-18-git-send-email-namhyung@kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>

tools/perf/ui/hist.c

@@ -513,6 +513,9 @@ void perf_hpp__column_disable(unsigned col)
 
 void perf_hpp__cancel_cumulate(void)
 {
+	if (field_order)
+		return;
+
 	perf_hpp__column_disable(PERF_HPP__OVERHEAD_ACC);
 	perf_hpp__format[PERF_HPP__OVERHEAD].header = hpp__header_overhead;
 }