rpmserver: Accept logging directory as argument in scripts.

We currently hard code the absolute path of the log file generated by
these scripts in rpm_config.ini
This is not maintainable in the lab, because there is no sane way to
override rpm_config.ini on the servers.

Instead, accept the logging directory via commandline.

BUG=chromium:762233
TEST=(1) unittests
     (2) Run rpmserver daemons via upstart.

Change-Id: I5485ae1a25536783b8f5a84d205f0b74bd5de4bc
Reviewed-on: https://chromium-review.googlesource.com/669946
Commit-Ready: Prathmesh Prabhu <pprabhu@chromium.org>
Tested-by: Prathmesh Prabhu <pprabhu@chromium.org>
Reviewed-by: Prathmesh Prabhu <pprabhu@chromium.org>
diff --git a/site_utils/rpm_control_system/rpm_dispatcher.py b/site_utils/rpm_control_system/rpm_dispatcher.py
index 7adfded..036553d 100755
--- a/site_utils/rpm_control_system/rpm_dispatcher.py
+++ b/site_utils/rpm_control_system/rpm_dispatcher.py
@@ -239,11 +239,12 @@
     Main function used to launch the dispatch server. Creates an instance of
     RPMDispatcher and registers it to a MultiThreadedXMLRPCServer instance.
     """
-    if len(sys.argv) > 1:
-      print 'Usage: ./%s, no arguments available.' % sys.argv[0]
+    if len(sys.argv) != 2:
+      print 'Usage: ./%s <log_file_name>' % sys.argv[0]
       sys.exit(1)
-    rpm_logging_config.start_log_server(LOG_FILENAME_FORMAT)
-    rpm_logging_config.set_up_logging(use_log_server=True)
+
+    rpm_logging_config.start_log_server(sys.argv[1], LOG_FILENAME_FORMAT)
+    rpm_logging_config.set_up_logging_to_server()
 
     # Get the local ip _address and set the server to utilize it.
     address = socket.gethostbyname(socket.gethostname())