Assignment instead of equality check?

There are several lines such as:
https://github.com/mit-racecar/vesc/blob/5127d60d8c9cadd2218f49a1b882b3c79710ec3a/vesc_driver/src/vesc_driver.cpp#L155

I believe these should be:
```
  if (driver_mode_ == MODE_OPERATING) {
```