qemuDomainBlockJobAbort: Don't use 'job-cancel' instead of 'block-job-cancel'
qemuDomainBlockJobAbort: Don't use 'job-cancel' instead of 'block-job-cancel'

'block-job-cancel' has one very important semantic difference to
'job-cancel', docummented in qemu as:

  Note that if you issue 'block-job-cancel' after 'drive-mirror' has indicated
  (via the event BLOCK_JOB_READY) that the source and destination are
  synchronized, then the event triggered by this command changes to
  BLOCK_JOB_COMPLETED, to indicate that the mirroring has ended and the
  destination now has a point-in-time copy tied to the time of the cancellation.

Since libvirt advertises the block copy job as having the synchronous
abort feature we must not use 'job-cancel' here.

Fixes: 4817b5ca1d0
Signed-off-by: Peter Krempa <2cf5c04c61aa466e4a47bfedc747d17279c72ffc@redhat.com>
Reviewed-by: Michal Privoznik <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>

libvirt/libvirt,olafhering/libvirt,nertpinx/libvirt,zippy2/libvirt,zippy2/libvirt,crobinso/libvirt,jfehlig/libvirt,libvirt/libvirt,libvirt/libvirt,olafhering/libvirt,crobinso/libvirt,crobinso/libvirt,nertpinx/libvirt,crobinso/libvirt,nertpinx/libvirt,nertpinx/libvirt,jfehlig/libvirt,jfehlig/libvirt,nertpinx/libvirt,zippy2/libvirt,olafhering/libvirt,zippy2/libvirt,olafhering/libvirt,libvirt/libvirt,jfehlig/libvirt