3w-xxxx: Pass through compat mode ioctls

This allows 32-bit userspace tools (tw_cli, smartctl) to work on a
64-bit system.  The command buffer is opaque to us, so, no word size
problems.
Signed-off-by: Ryan C. Underwood <nemesis@icequake.net>
Reviewed-by: Shane Seymour <shane.seymour@hpe.com>
Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/3w-xxxx.c

@@ -1045,6 +1045,9 @@ static int tw_chrdev_open(struct inode *inode, struct file *file)
 static const struct file_operations tw_fops = {
 	.owner		= THIS_MODULE,
 	.unlocked_ioctl	= tw_chrdev_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl   = tw_chrdev_ioctl,
+#endif
 	.open		= tw_chrdev_open,
 	.release	= NULL,
 	.llseek		= noop_llseek,