perf mem: Fill in the missing session freeing after an error occurs

When an error occurs an error value is just returned without freeing the
session. So allocating and freeing session have to be matched as a pair
even if an error occurs.

Signed-off-by: Taeung Song <[e-mail]>
Acked-by: Jiri Olsa <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/builtin-mem.c

···
 		.mode = PERF_DATA_MODE_READ,
 		.force = mem->force,
 	};
-	int err = -EINVAL;
 	int ret;
 	struct perf_session *session = perf_session__new(&file, false,
 							 &mem->tool);
···
 	if (mem->cpu_list) {
 		ret = perf_session__cpu_bitmap(session, mem->cpu_list,
 					       mem->cpu_bitmap);
-		if (ret)
+		if (ret < 0)
 			goto out_delete;
 	}
 
-	if (symbol__init(&session->header.env) < 0)
-		return -1;
+	ret = symbol__init(&session->header.env);
+	if (ret < 0)
+		goto out_delete;
 
 	printf("# PID, TID, IP, ADDR, LOCAL WEIGHT, DSRC, SYMBOL\n");
 
-	err = perf_session__process_events(session);
-	if (err)
-		return err;
-
-	return 0;
+	ret = perf_session__process_events(session);
 
 out_delete:
 	perf_session__delete(session);
-	return err;
+	return ret;
 }
 
 static int report_events(int argc, const char **argv, struct perf_mem *mem)