atapi: fix halted DMA reset

Followup to 87ac25fd, this time for ATAPI DMA.

Reported-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 1470164128-28158-1-git-send-email-jsnow@redhat.com
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
(cherry picked from commit 7f951b2d)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>