documentation typos

[Aleix Conchillo Flaqué]

I just found some minor typos in 4.6.6 which are still inherited in
current documentation.

* rtems_task_delete:

    RTEMS_ILLEGAL_ON_REMOTE_OBJECT - cannot restart remote task
         ---> cannot delete remote task

* rtems_task_suspend:

    RTEMS_SUCCESSFUL - task restarted successfully
        ---> task suspended successfully

* rtems_task_resume:

    RTEMS_SUCCESSFUL - task restarted successfully
        ---> task resumed successfully

Cheers,

Aleix