The first argument was previously $manpage, but we effectively only
worked with a previously-set $manpage anyways; stop pretending that the
argument matters and just pass the path of interest in.
This previously relied on $path being set in the caller, but that only
worked coincidentally in the search loop for non-paths. This fixes
.so references when a path to a manpage has been provided rather than
just the name/section of a manpage.
While here, fix the path we pass in while searching for .so references
during the relative/absolute path case. .so references are w.r.t. to a
mandir, not a mandir/section.
Sponsored by: Klara, Inc.