[SCSI] qla2xxx: Handle failure cases during fabric_login

Make sure that all calls to ha->isp_ops->fabric_login() check the
return value for failure.

Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: Chad Dupuis <chad.dupuis@qlogic.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>