Use the string representation for logging

Now that we have nice string representations, it is no longer needed to
build one every time we log something.

Signed-off-by: Leandro Lucarella <[email protected]>

Author: llucax

src/frequenz/channels/_broadcast.py

@@ -327,9 +327,8 @@ def enqueue(self, msg: T) -> None:
         if len(self._q) == self._q.maxlen:
             self._q.popleft()
             logger.warning(
-                "Broadcast receiver [%s:%s] is full. Oldest message was dropped.",
-                self._chan._name,  # pylint: disable=protected-access
-                self._name,
+                "Broadcast receiver [%s] is full. Oldest message was dropped.",
+                self,
             )
         self._q.append(msg)