blockjob: Update block-job-pause/resume documentation

Commit 0ec4dfb8d changed block-job_pause/resume so that they return an
error if they don't do anything because the job is already
paused/running. It forgot to update the documentation, so do that now.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
1 file changed