Merge remote-tracking branch 'bonzini/scsi-next' into staging

Merge remote-tracking branch 'bonzini/scsi-next' into staging

# By Paolo Bonzini (4) and Peter Lieven (2)
# Via Paolo Bonzini
* bonzini/scsi-next:
  scsi-disk: handle io_canceled uniformly and correctly
  scsi-disk: do not complete canceled UNMAP requests
  scsi: do not call scsi_read_data/scsi_write_data for a canceled request
  iscsi: look for pkg-config file too
  iscsi: add iscsi_truncate support
  iscsi: retry read, write, flush and unmap on unit attention check conditions