b6868e2f47
Use the first found directory in the tar archive instead of relying on
a directory named according to the userspace boardname.
It allows to change the boardname without adding another compatibility
layer to the zyxel sysupgrade.
Fixes: 33f09cf151 ("ipq806x: convert to dt-based board-detection")
Signed-off-by: Mathias Kresin <dev@kresin.me>