am a3ae60d3: libc: Add missing fdatasync() implementation

Merge commit 'a3ae60d343661784e3f6f4566b276d8e6b8a06a7' into gingerbread-plus-aosp

* commit 'a3ae60d343661784e3f6f4566b276d8e6b8a06a7':
  libc: Add missing fdatasync() implementation