[SCSI] scsi_transport_spi: fix sense buffer size error

The code does this:

unsigned char sense[SCSI_SENSE_BUFFERSIZE];
...
scsi_normalize_sense(sense, sizeof(*sense), sshdr)

however the sizeof will return 1 not 96 which means the sense data will
have no valid ASC/ASCQ values.  Fix by putting the correct sense size.
The only affected case for this would have been the DV buffer sanity
check failure, which is fortunately quite rare.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>