Trace external pointers from helpers

At this time, a single helper can return a kernel pointer,
bpf_get_current_task.
diff --git a/tools/cpuunclaimed.py b/tools/cpuunclaimed.py
index 364e80e..58b8e4a 100755
--- a/tools/cpuunclaimed.py
+++ b/tools/cpuunclaimed.py
@@ -144,8 +144,8 @@
     struct task_struct *task = NULL;
     struct cfs_rq_partial *my_q = NULL;
     task = (struct task_struct *)bpf_get_current_task();
-    bpf_probe_read(&my_q, sizeof(my_q), &task->se.cfs_rq);
-    bpf_probe_read(&len, sizeof(len), &my_q->nr_running);
+    my_q = (struct cfs_rq_partial *)task->se.cfs_rq;
+    len = my_q->nr_running;
 
     struct data_t data = {.ts = now, .cpu = cpu, .len = len};
     events.perf_submit(ctx, &data, sizeof(data));