fix pylint

Author: vladak

adafruit_minimqtt/adafruit_minimqtt.py

@@ -871,21 +871,19 @@ def unsubscribe(self, topic: str) -> None:
         self.logger.debug("Waiting for UNSUBACK...")
         while True:
             op = self._wait_for_msg()
-            if op:
-                if op == 176:
-                    rc = self._sock_exact_recv(3)
-                    assert rc[0] == 0x02
-                    # [MQTT-3.32]
-                    assert rc[1] == packet_id_bytes[0] and rc[2] == packet_id_bytes[1]
-                    for t in topics:
-                        if self.on_unsubscribe is not None:
-                            self.on_unsubscribe(self, self._user_data, t, self._pid)
-                        self._subscribed_topics.remove(t)
-                    return
-                else:
-                    raise MMQTTException(
-                        f"invalid message received as response to UNSUBSCRIBE: {hex(op)}"
-                    )
+            if op == 176:
+                rc = self._sock_exact_recv(3)
+                assert rc[0] == 0x02
+                # [MQTT-3.32]
+                assert rc[1] == packet_id_bytes[0] and rc[2] == packet_id_bytes[1]
+                for t in topics:
+                    if self.on_unsubscribe is not None:
+                        self.on_unsubscribe(self, self._user_data, t, self._pid)
+                    self._subscribed_topics.remove(t)
+            else:
+                raise MMQTTException(
+                    f"invalid message received as response to UNSUBSCRIBE: {hex(op)}"
+                )
 
     def _recompute_reconnect_backoff(self) -> None:
         """