cmdutil: migrate previously missed instances to uipathfn

Authored by martinvonz.

Description

cmdutil: migrate previously missed instances to uipathfn

I seem to have missed these two instances in 15f63ac122ea (files:
respect ui.relative-paths, 2019-01-29) and 7068c6b0114b (revert:
respect ui.relative-paths, 2019-02-05).

Differential Revision: https://phab.mercurial-scm.org/D5915