devserver: Use chromite's logging library

We're removing cherrypy_log_util.py and its better to just use the
chromite's version of logging.

BUG=b:186066529
TEST=./devserver.py

Cq-Depend: chromium:2856532
Change-Id: Ibec85bb3f789baf831666c04405f4291d522176a
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/2856530
Tested-by: Amin Hassani <ahassani@chromium.org>
Reviewed-by: Keith Haddow <haddowk@chromium.org>
Reviewed-by: Ivan Brovkovich <ivanbrovkovich@chromium.org>
Commit-Queue: Amin Hassani <ahassani@chromium.org>
diff --git a/builder.py b/builder.py
index 200cb35..4f22614 100644
--- a/builder.py
+++ b/builder.py
@@ -15,7 +15,7 @@
 import cherrypy  # pylint: disable=import-error
 
 import setup_chromite  # pylint: disable=unused-import
-from chromite.lib.xbuddy import cherrypy_log_util
+from chromite.lib import cros_logging as logging
 
 
 # Relative path to the wrapper directory inside the sysroot.
@@ -34,7 +34,7 @@
 
 # Module-local log function.
 def _Log(message, *args):
-  return cherrypy_log_util.LogWithTag('BUILD', message, *args)
+  return logging.info(message, *args)
 
 
 def _OutputOf(command):