fix vars named l

E741 says "do not use variables named ‘l’, ‘O’, or ‘I’".

synapse/util/__init__.py

@@ -59,9 +59,9 @@ class Clock(object):
             f(function): The function to call repeatedly.
             msec(float): How long to wait between calls in milliseconds.
         """
-        l = task.LoopingCall(f)
-        l.start(msec / 1000.0, now=False)
-        return l
+        call = task.LoopingCall(f)
+        call.start(msec / 1000.0, now=False)
+        return call
 
     def call_later(self, delay, callback, *args, **kwargs):
         """Call something later

synapse/util/wheel_timer.py

@@ -91,7 +91,4 @@ class WheelTimer(object):
         return ret
 
     def __len__(self):
-        l = 0
-        for entry in self.entries:
-            l += len(entry.queue)
-        return l
+        return sum(len(entry.queue) for entry in self.entries)