ima: fix ima_show_template_data_ascii()

[ Upstream commit 45b26133b97871896b8c5241d59f4ff7839db7b2 ]

This patch fixes a bug introduced in "4d7aeee7 ima: define new template
ima-ng and template fields d-ng and n-ng".

Changelog:
- change int to uint32 (Roberto Sassu's suggestion)

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Roberto Sassu <rsassu@suse.de>
Cc: stable@vger.kernel.org # 3.13
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>