Switch to go version of the swarming tool.

Change-Id: I6504ca383c342cb6c2e23ca5ad5cdb450744398b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2245419
Reviewed-by: Takuto Ikuta <tikuta@chromium.org>
Reviewed-by: Fergal Daly <fergal@chromium.org>
Commit-Queue: Fergal Daly <fergal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#778199}

tools/get_swarming_logs/get_one.sh

@@ -21,7 +21,6 @@ shift
 
 out="$base_dir/$id.txt"
 mkdir -p "$base_dir"
-python tools/swarming_client/swarming.py \
-    collect -S chromium-swarm.appspot.com "$id" > "$out" \
-    || true
+tools/luci-go/swarming collect -task-output-stdout=console \
+    -S chromium-swarm.appspot.com "$id" > "$out"
 echo "$out"