perf report: Fix sample type validation for synthesized callchains

Processing instruction tracing data (e.g. Intel PT) can synthesize
callchains e.g.

	$ perf record -e intel_pt//u uname
	$ perf report --stdio --itrace=ige

However perf report's callgraph option gets extra validation, so:

	$ perf report --stdio --itrace=ige -gflat
	Error:
	Selected -g or --branch-history but no callchain data. Did
	you call 'perf record' without -g?
	# To display the perf.data header info,
	# please use --header/--header-only options.
	#

Fix the validation to know about instruction tracing options so
above command works.

A side-effect of the change is that the default option to
accumulate the callchain of child functions comes into force.
To get the previous behaviour the --no-children option can be
used e.g.

       $ perf report --stdio --itrace=ige -gflat --no-children

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1443186956-18718-3-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-report.c

@@ -214,6 +214,12 @@ static int report__setup_sample_type(struct report *rep)
 	u64 sample_type = perf_evlist__combined_sample_type(session->evlist);
 	bool is_pipe = perf_data_file__is_pipe(session->file);
 
+	if (session->itrace_synth_opts->callchain ||
+	    (!is_pipe &&
+	     perf_header__has_feat(&session->header, HEADER_AUXTRACE) &&
+	     !session->itrace_synth_opts->set))
+		sample_type |= PERF_SAMPLE_CALLCHAIN;
+
 	if (!is_pipe && !(sample_type & PERF_SAMPLE_CALLCHAIN)) {
 		if (sort__has_parent) {
 			ui__error("Selected --sort parent, but no "