r395: - Fix thinko in transform_alloc() compression allocation
r395: - Fix thinko in transform_alloc() compression allocation

- Add explicit sanity check for supported_compression == 0

- Correct error message in invalid-default-compression case

cmusatyalab/openisr,cmusatyalab/openisr,cmusatyalab/openisr,cmusatyalab/openisr,cmusatyalab/openisr