[BUG] Ensure "/" and "/boot" don't get pulled in my `MkChrootTree.sh`

[ferricoxide]

Describe the bug
When using build-scripts to facilitate a chroot()ed build for VMware, current logic can result in / and/or /boot being overlay-mounted on top of the desired / and /boot in the chroot() target

Severity
Manual edit of MkChrootTree.sh required to surmount

To Reproduce
Steps to reproduce the behavior:

1. Launch work-host under VMware
2. Start hand-executing AMIgen7 scripts
3. Run MkChrootTree.sh
4. Note that the mounts in the chroot() target are "missing" (not present in df output but present in /proc/mounts)

Expected behavior

Neither the / nor the /boot from the boot-OS should be mounted into the chroot()

Fix Suggestions
Add /\/ /d and /\/boot /d to partition-setup sed block for the MkChrootTree.sh script