[SCSI] mptfusion - mapping fixs required support for transport layers.

This utilizes the hostdata area that is hung off of scsi_target and
scsi_device for saving unique firmware mapping. This will be required
for supporting new Fibre and SPI transport support.

This also fixs problems in error handling error code for SAS
controllers, in which the incorrect mapping was passed to the
firmware.

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