_pull_valid_cache: pass unicode to hashed_path

_pull_valid_cache: pass unicode to hashed_path

This removes a conversion to bytes that should have been removed in
commit 2ed1cb53cc4158af08c22d466b15b9a9a7767212. The hashed_path
location attribute should always be unicode, for consistency will path
handling throughout portage. The hashed_path class internally uses the
portage portage.os wrapper to ensure that paths are encoded as utf_8
bytes when they are passed to the real os module for stat calls.