Fixed an error message formatting

Author: pylessard

isotp/protocol.py

@@ -941,7 +941,7 @@ def get_dlc(self, data, validate_tx=False):
         elif fdlen == 32: return 13
         elif fdlen == 48: return 14
         elif fdlen == 64: return 15
-        raise ValueError("Impossible DLC size for payload of %d bytes with tx_data_length of %d" % (len(data)))
+        raise ValueError("Impossible DLC size for payload of %d bytes with tx_data_length of %d" % (len(data), self.params.tx_data_length))