scsi: st: Modify st.c to use the new scsi_error counters

scsi: st: Modify st.c to use the new scsi_error counters

Compare the stored values of por_ctr and new_media_ctr against the values
in the device struct. In case of mismatch, the Unit Attention corresponding
to the counter has happened.  This is a safeguard against another ULD
catching the Unit Attention sense data.

Macros scsi_get_ua_new_media_ctr and scsi_get_ua_por_ctr are added to read
the current values of the counters.

Signed-off-by: Kai Mäkisara <Kai.Makisara@kolumbus.fi>
Link: https://lore.kernel.org/r/20250120194925.44432-4-Kai.Makisara@kolumbus.fi
Reviewed-by: John Meneghini <jmeneghi@redhat.com>
Tested-by: John Meneghini <jmeneghi@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>