scsi: scsi_ioctl: Add kernel-doc for exported functions

scsi: scsi_ioctl: Add kernel-doc for exported functions

Add kernel-doc for scsi_set_medium_removal(), scsi_cmd_allowed(), and
scsi_ioctl_block_when_processing_errors() since these are exported.  This
allows them to be part of the SCSI driver-api docbook.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20241212205217.597844-3-rdunlap@infradead.org
CC: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
CC: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>