tree-wide: fix a number of log calls that use %m but have no errno set

tree-wide: fix a number of log calls that use %m but have no errno set

This is mostly fall-out from d1a1f0aaf0d2f08c60d1e0d32e646439d99f58dc,
however some cases are older bugs.

There might be more issues lurking, this was a simple grep for "%m"
across the tree, with all lines removed that mention "errno" at all.