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 <[e-mail]>
Acked-by: Don Brace <[e-mail]>
Signed-off-by: Martin K. Petersen <[e-mail]>

drivers/scsi/hpsa.c

···
 	case WRITE_6:
 	case WRITE_12:
 		is_write = 1;
+		/* fall through */
 	case READ_6:
 	case READ_12:
 		if (*cdb_len == 6) {
···
 	switch (cmd->cmnd[0]) {
 	case WRITE_6:
 		is_write = 1;
+		/* fall through */
 	case READ_6:
 		first_block = (((cmd->cmnd[1] & 0x1F) << 16) |
 				(cmd->cmnd[2] << 8) |
···
 		break;
 	case WRITE_10:
 		is_write = 1;
+		/* fall through */
 	case READ_10:
 		first_block =
 			(((u64) cmd->cmnd[2]) << 24) |
···
 		break;
 	case WRITE_12:
 		is_write = 1;
+		/* fall through */
 	case READ_12:
 		first_block =
 			(((u64) cmd->cmnd[2]) << 24) |
···
 		break;
 	case WRITE_16:
 		is_write = 1;
+		/* fall through */
 	case READ_16:
 		first_block =
 			(((u64) cmd->cmnd[2]) << 56) |