darwin: Always use GetPipePropertiesV3 when available

The V3 API goes back to macOS 10.8.2 (2012), and we have already been
using it when targeting 10.9 or higher for a while. However in a few
places we were still using the older API.

Affects get_endpoints() and submit_iso_transfer().

In the latter also:
- Check success of pipe properties retrieval.
- Remove a duplicate call to GetPipeProperties().

References #919
Closes #1056

Signed-off-by: Tormod Volden <debian.tormod@gmail.com>
2 files changed