perf tools: Fix memory leak when synthesizing thread records

Checking default guest machine should be done before allocating event
structures otherwise it'll leak memory.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Joe Mario <jmario@redhat.com>
Link: http://lkml.kernel.org/r/87ob15tx6a.fsf@sejong.aot.lge.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/event.c

@@ -446,6 +446,9 @@ int perf_event__synthesize_threads(struct perf_tool *tool,
 	union perf_event *comm_event, *mmap_event, *fork_event;
 	int err = -1;
 
+	if (machine__is_default_guest(machine))
+		return 0;
+
 	comm_event = malloc(sizeof(comm_event->comm) + machine->id_hdr_size);
 	if (comm_event == NULL)
 		goto out;
@@ -458,9 +461,6 @@ int perf_event__synthesize_threads(struct perf_tool *tool,
 	if (fork_event == NULL)
 		goto out_free_mmap;
 
-	if (machine__is_default_guest(machine))
-		return 0;
-
 	snprintf(proc_path, sizeof(proc_path), "%s/proc", machine->root_dir);
 	proc = opendir(proc_path);