[PATCH 5.4/5.10 0/1] mac80211: mesh: embedd mesh_paths and mpp_paths into ieee80211_if_mesh

The null-ptr-deref problem fixed in the following patch is hit on older branches.

The patch failed to be initially backported into stable branches older than 5.15 due to the fix-spell-comment commit ab4040df6efb ("mac80211: fix some spelling mistakes"). Now it can be cleanly applied to the 5.4/5.10 stable branches.

I'm not sure if the comment-fix patch should be backported in these cases, too (to prevent similar potential future backport fails). Probably not. So I just adapted the backport patch in-place.