[SCSI] ibmvscsi timeout fix

This patch fixes a long term borkenness in
ibmvscsi where we were using the wrong timeout
field from the scsi command (and using the
wrong units.)  Now broken by the fact that the
scsi_cmnd timeout field is gone entirely.
This only worked before because all the SCSI
targets assumed that 0 was default.

Signed-off-by: Dave Boutcher <boutcher@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>