More O_DIRECTORY | O_NOFOLLOW changes

Fix a few other spots where we're not using O_NOFOLLOW
with O_DIRECTORY.

Add O_CLOEXEC for good measure.

https://code.google.com/p/android/issues/detail?id=181945

Bug: 23044050
Change-Id: Ib535cbba29cdd587443ea9e1e75831f57fd7a93c