[SCSI] ipr: Better handle failure of adapter bringup commands

Some new ipr adapters do not support some of the initialization
commands currently sent to it from the driver. Handle these
commands failing and continue on with the adapter initialization.

Signed-off-by: Brian King <brking@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>