Add wrongly removed statement back to codebase (#612)

* Add wrongly removed statement back to codebase

This was removed in the process of making the linter happy. But it is required since it changes `num_channels`.

* remove unused commented out logging

Author: felixdivo

can/interfaces/kvaser/canlib.py

@@ -424,7 +424,7 @@ def __init__(self, channel, can_filters=None, **kwargs):
         self.single_handle = single_handle
 
         num_channels = ctypes.c_int(0)
-        # log.debug("Res: %d", canGetNumberOfChannels(ctypes.byref(num_channels)))
+        canGetNumberOfChannels(ctypes.byref(num_channels))
         num_channels = int(num_channels.value)
         log.info("Found %d available channels", num_channels)
         for idx in range(num_channels):