pathcanon: avoid reusing `dots` variable for unrelated values

pathcanon: avoid reusing `dots` variable for unrelated values

This branch reuses the `dots` variable, previously used for counting the number
of periods in the path, for storing the result of symlink resolution. This is
unnecessary (`dots` is immediately overwritten with the value 4 after this), and
is getting in the way of cleaning up some compiler warnings in this area.