gettime: remember to tear down clock cpumask on normal exit

Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/gettime.c b/gettime.c
index 8bc8413..6863ce3 100644
--- a/gettime.c
+++ b/gettime.c
@@ -528,6 +528,7 @@
 	if (!t->entries[i - 1].tsc && !t->entries[0].tsc)
 		goto err;
 
+	fio_cpuset_exit(&cpu_mask);
 	return NULL;
 err:
 	fio_cpuset_exit(&cpu_mask);