Comment 2 for bug 1652091

First of all, affected package is dropbear-initramfs, not dropbear.

Offending line in "/usr/share/initramfs-tools/scripts/init-bottom/dropbear" script is supposed to kill all dropbear children.

There are two problems with it:
1. The "ps" command (part of busybox, of busybox-initramfs, here 1:1.22.0-15ubuntu1) does not support options: -eo ppid,pid
2. As mentioned, "xargs" is missing entirely in initrd

Proposed solution is based on facts, that:
- there is "ps -l" which outputs PID and PPID (as 3rd and 4th column)
- there is awk
- in this case, xargs can be easily replaced with shell construct

Solution was succesfully tested on our servers.