iotests: add pause_wait

Split out the pause command into the actual pause and the wait.
Not every usage presently needs to resubmit a pause request.

The intent with the next commit will be to explicitly disallow
redundant or meaningless pause/resume requests, so the tests
need to become more judicious to reflect that.

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