scsi: pm8001: Add descriptions for unused 'attr' function parameters

scsi: pm8001: Add descriptions for unused 'attr' function parameters

Clean-up some whitespace issues too whilst we're here.

Fixes the following W=1 kernel build warning(s):

 drivers/scsi/pm8001/pm8001_ctl.c:102: warning: Function parameter or member 'attr' not described in 'pm8001_ctl_fw_version_show'
 drivers/scsi/pm8001/pm8001_ctl.c:331: warning: Function parameter or member 'attr' not described in 'pm8001_ctl_logging_level_show'
 drivers/scsi/pm8001/pm8001_ctl.c:400: warning: Function parameter or member 'attr' not described in 'pm8001_ctl_ib_queue_log_show'
 drivers/scsi/pm8001/pm8001_ctl.c:433: warning: Function parameter or member 'attr' not described in 'pm8001_ctl_ob_queue_log_show'
 drivers/scsi/pm8001/pm8001_ctl.c:464: warning: Function parameter or member 'attr' not described in 'pm8001_ctl_bios_version_show'
 drivers/scsi/pm8001/pm8001_ctl.c:623: warning: Function parameter or member 'attr' not described in 'pm8001_ctl_gsm_log_show'

Link: https://lore.kernel.org/r/20200721164148.2617584-12-lee.jones@linaro.org
Cc: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>