Fix the bug that added the bytes_received value to itself at each count

[galexo]

The value of bytes_received was added to itself at every loop step:

bytes_received += bytes_received + node.bytes_received
bytes_sent = bytes_sent + node.bytes_sent

Changed it so it correctly adds only the nodes.bytes_received value and also changed the next line for consistency:

bytes_received += node.bytes_received
bytes_sent += node.bytes_sent