[FS#220] x86: combined squashfs use tmpfs as overlay

[LEDE Bugs]

The following task has a new comment added:

FS#220 - x86: combined squashfs use tmpfs as overlay
User who did this - Felix Fietkau (nbd)

----------
Please check if mkf2fs and e2fsprogs are enabled in your config.
----------

More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=220#comment666