Revert "ext4: dax: fix overflowing extents beyond inode size when partially writing"

This reverts commit f8a7c342 which is
commit dda898d7 upstream.

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

Bug: 161946584
Change-Id: I8c5a06731ef7830612591c6f818ac69cf169d78a
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>