Revert "ext4: fix use-after-free in ext4_xattr_set_entry"

This reverts commit bb8592ef which is
commit 67d7d8ad upstream.

The order in which patches are queued to stable matters. This patch
has a logical dependency on commit 310c097c
upstream, and failing to queue the latter results in a null-ptr-deref
reported at the Link below.

In order to avoid conflicts on stable, revert the commit just so that we
can queue its prerequisite patch first and then queue the same after.

Link: https://syzkaller.appspot.com/bug?extid=d5ebf56f3b1268136afd


Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>