perf stat: Fix memory leak on error path

strdup() is used to deduplicate, ensure it isn't leaking an already
created string by freeing first.

Signed-off-by: Ian Rogers <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: John Garry <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Author: captain5050

tools/perf/util/stat-shadow.c

@@ -444,6 +444,7 @@ void perf_stat__collect_metric_expr(struct evlist *evsel_list)
 						"Add %s event to groups to get metric expression for %s\n",
 						metric_name,
 						counter->name);
+					free(printed);
 					printed = strdup(metric_name);
 				}
 				invalid = true;