Update location of luc-milo.cfg mentioned in comment.

Bug: None
Change-Id: I1f436a10c64f9e8ca59dfbe0d811cfc6904ca680
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2530257
Commit-Queue: benjamin joyce <bjoyce@chromium.org>
Reviewed-by: Brian Sheedy <bsheedy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#825953}

testing/buildbot/generate_buildbot_json.py

@@ -1364,7 +1364,7 @@ class BBJSONGenerator(object):
       self.write_file(self.pyl_file_path(filename + suffix), jsonstr)
 
   def get_valid_bot_names(self):
-    # Extract bot names from infra/config/luci-milo.cfg.
+    # Extract bot names from infra/config/generated/luci-milo.cfg.
     # NOTE: This reference can cause issues; if a file changes there, the
     # presubmit here won't be run by default. A manually maintained list there
     # tries to run presubmit here when luci-milo.cfg is changed. If any other