[benchmarking] Docs link to googlesource rather than github.

GitHub mirror is not being used anymore, so better
to use the main source for the docs link.

Bug: 1059913w
Change-Id: Iab2d7e1eb180a6a79e4487e827e6e1f97edb1edf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2116785
Auto-Submit: Caleb Rouleau <crouleau@chromium.org>
Reviewed-by: John Chen <johnchen@chromium.org>
Commit-Queue: John Chen <johnchen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#752643}

docs/speed/benchmark/benchmark_short_list.md

@@ -25,5 +25,5 @@ Both desktop & mobile:
 
 
 Instructions for how to run these benchmarks:
-*   [Running them locally](https://github.com/catapult-project/catapult/blob/master/telemetry/docs/run_benchmarks_locally.md)
+*   [Running them locally](https://chromium.googlesource.com/catapult/+/master/telemetry/docs/run_benchmarks_locally.md)
 *   [Running on perf trybot](https://chromium.googlesource.com/chromium/src/+/master/docs/speed/perf_trybots.md)