BUG/MEDIUM: tasks: Don't forget to increase/decrease tasks_run_queue.

Don't forget to increase tasks_run_queue when we're adding a task to the
tasklet list, and to decrease it when we remove a task from a runqueue,
or its value won't be accurate, and could lead to tasks not being executed
when put in the global run queue.

1.9-dev only, no backport is needed.
1 file changed