[SCSI] ibmvscsi: Fix module load hang

Fixes a regression seen in the ibmvscsi driver when using the VSCSI
server in SLES 9 and SLES 10. The VSCSI server in these releases
has a bug in it in which it does not send responses to unknown MADs.
Check the OS Type field in the adapter info response and do not send
these unsupported commands when talking to an older server.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>