Revert "ext4: properly sync file size update after O_SYNC direct IO"

This reverts commit dde4c1e1 which is
commit 91562895 upstream.

It breaks the Android kernel tests, and can be brought back in the future
if it is really needed.

Bug: 161946584
Change-Id: Ia4acc78370c913f2c3691a68148db000f3034eaf
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>