scsi: hpsa: mark expected switch fall-throughs

In preparation to enabling -Wimplicit-fallthrough, mark switch cases where
we are expecting to fall through.

Addresses-Coverity-ID: 1195463 ("Missing break in switch")
Addresses-Coverity-ID: 1195464 ("Missing break in switch")
Addresses-Coverity-ID: 1195465 ("Missing break in switch")
Addresses-Coverity-ID: 1195466 ("Missing break in switch")
Addresses-Coverity-ID: 1357338 ("Missing break in switch")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: Don Brace <don.brace@microsemi.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>