The function job_cancel_async() will always cause an assert for blockjob
user resume.  We set job->user_paused to false, and then call
job->driver->user_resume().  In the case of blockjobs, this is the
block_job_user_resume() function.

In that function, we assert that job.user_paused is set to true.
Unfortunately, right before calling this function, it has explicitly
been set to false.

The fix is pretty simple: set job->user_paused to false only after the
job user_resume() function has been called.

Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Message-id: bb183b77d8f2dd6bd67b8da559a90ac1e74b2052.1534868459.git.jcody@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>