[ Upstream commit 97daf8b9 ]

When ovl_copy_xattr() encountered a zero size xattr no more xattrs were
copied and the function returned success.  This is clearly not the desired
behavior.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Cc: <stable@vger.kernel.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>