Relaxed CORB read pointer reset checking for nVidia HDA

* At least some nVidia HDA controllers do not acknowledge the CORB
  read pointer reset, which is required by the spec (cf. HDA 1.0a
  ch. 3.3.21). For these controllers, do not fail when acknowledge
  is missing.

* Makes hda driver work for nVidia HDA controllers again, thus fixing
  the regression pointed out in #10212.
Style fix: line length