Revert external/hidapi to an older commit

The previous update to the latest hidapi upstream introduced changes that
break HID Feature reports on Windows. This fix sets the hidapi submodule to
the commit preceeding the problematic one.

For a description of the problem see hidapi's issue list:

  https://github.com/signal11/hidapi/issues/192
Merge pull request #134 from nitsch/rollback-hidapi

Revert external/hidapi to an older commit