i2o proc reading oops

Fix oops on reading from some i2o proc files (i2o_seq_show_driver_store() and
other) because their handlers uses "exec" field in struct i2o_controller

Signed-off-by: Vasily Averin <[e-mail]>
Acked-by: Alan Cox <[e-mail]>
Cc: Markus Lidel <[e-mail]>
Acked-by: Kirill Korotaev <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/message/i2o/exec-osm.c

···
 	rc = device_create_file(dev, &dev_attr_product_id);
 	if (rc) goto err_vid;
 
+	i2o_dev->iop->exec = i2o_dev;
+
 	return 0;
 
 err_vid: