* disk/scsi.c (grub_scsi_read10): Use scsi->blocksize instead
of 512 to calculate data size.
(grub_scsi_read12): Likewise.
(grub_scsi_write10): Likewise.
(grub_scsi_write12): Likewise.
(grub_scsi_read): Adjust size according to blocksize.
Add checks for invalid blocksize and unaligned transfer.