perf tools: sort_dimension__add shouldn't die

Propagate error instead.

LKML-Reference: <new-submission>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-report.c

@@ -473,7 +473,8 @@ int cmd_report(int argc, const char **argv, const char *prefix __used)
 	setup_sorting(report_usage, options);
 
 	if (parent_pattern != default_parent_pattern) {
-		sort_dimension__add("parent");
+		if (sort_dimension__add("parent") < 0)
+			return -1;
 		sort_parent.elide = 1;
 	} else
 		symbol_conf.exclude_other = false;