scsi: scsi_ioctl: Call scsi_cmd_ioctl() from scsi_ioctl()

Ensure SCSI ULD only has to call a single ioctl helper.  This also adds a
bunch of missing ioctls to the ch driver, and removes the need for a
duplicate implementation of SCSI_IOCTL_SEND_COMMAND command.

Link: https://lore.kernel.org/r/20210724072033.1284840-12-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>