[FS#367] mkhash causes error in feed update after make dirclean (always if prereq has not yet been run)

[LEDE Bugs]

The following task is now closed:

FS#367 - mkhash causes error in feed update after make dirclean (always if prereq has not yet been run)
User who did this - Felix Fietkau (nbd)

Reason for closing: Fixed
More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=367