R1:2d4a158356ef

Fix a bad link target in Diffusion content search results

Summary: See <https://discourse.phabricator-community.org/t/broken-links-in-diffusion-pattern-search-results-page/757>. This links to the display path, which is incorrect.

Test Plan:
- In any repository, browsed into a directory.
- Used pattern search to search for something that hits results.
- Clicked the title (filename/path) of a result table.
- Before patch: URL omits path context, 404 or wrong result.
- After patch: taken to…