Merge remote-tracking branch 'origin/upstream-f2fs-stable-linux-3.18.y' into android-3.18

* origin/upstream-f2fs-stable-linux-3.18.y:
  Revert "f2fs: use timespec64 for inode timestamps"

Change-Id: I16c7682a67920a0e193177615c76bdf03c62d6cf
Signed-off-by: Jaegeuk Kim <jaegeuk@google.com>