Replace "getRequestURI()->setQueryParams(array())" with "getPath()"

Summary:
Ref T13250. A handful of callsites are doing getRequestURI() + setQueryParams(array()) to get a bare request path.

They can just use getPath() instead.

Test Plan: See inlines.

Reviewers: amckinley

Reviewed By: amckinley

Maniphest Tasks: T13250

Differential Revision: https://secure.phabricator.com/D20150