[SCSI] Fix incorrect reporting of host protection capabilities

The advent of DIF Type 2 devices exposed some missing break statements
in the protection mask switch constructs.  However, rewriting the code
to use an index into a small static array seemed like a more elegant
solution.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>