util-linux vulnerability

USN-6719-1 fixed a vulnerability in util-linux. Unfortunately, it was
discovered that the fix did not fully address the issue. This update
removes the setgid permission bit from the wall and write utilities.

Original advisory details:

Skyler Ferrante discovered that the util-linux wall command did not filter
escape sequences from command line arguments. A local attacker could
possibly use this issue to obtain sensitive information.