scsi-disk: rd/wr/vr-protect !=0 is an error

The QEMU SCSI emulation does not support protection information,
so any READ/WRITE/VERIFY commands that has the protect bits set to
non-zero should fail with ILLEGAL_REQUEST/INVALID_FIELD_IN_CDB

From SCSI SBC :
If the logical unit does not support protection information,
then the device server should terminate the command with CHECK CONDITION
status with the sense key set to ILLEGAL REQUEST and the additional sense
code set to INVALID FIELD IN CDB.

Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
[ Rebase after scsi_dma_reqops introduction - Paolo ]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
