BUG/MEDIUM: tasks: Decrement rqueue_size at the right time.

We need to decrement requeue_size when we remove a task form rqueue_local,
not when we remove if from the task list, or we'd also decrement it for any
tasklet, that was never in the rqueue in the first place.
diff --git a/src/task.c b/src/task.c
index 86833cf..edb528a 100644
--- a/src/task.c
+++ b/src/task.c
@@ -333,6 +333,7 @@
 
 		/* detach the task from the queue */
 		__task_unlink_rq(t);
+		rqueue_size[tid]--;
 		/* And add it to the local task list */
 		task_insert_into_tasklet_list(t);
 	}
@@ -349,7 +350,6 @@
 
 		ctx = t->context;
 		process = t->process;
-		rqueue_size[tid]--;
 		t->calls++;
 		curr_task = (struct task *)t;
 		if (likely(process == process_stream))