recognize zram as swap

[chri2]

Check if unencrypted swap is zram. If it is zram check whether a writeback to disk is configured.

Unencrypted zramswap not written to disk is accepted.

ToDo (as for other unencrypted swap): check if the writeback happens on an already encrypted disk/partition.

[chri2]

recognizes zramswap as swap that lives in ram only if it doesn't write back to disk

https://github.com/dyne/Tomb/issues/445

[jaromil]

thanks for your contribution and be welcome among tomb developers! 🎉

[chri2]

:partying_face: