checkstyle.sh is failing

Running `checkstyle.sh` on mainline produces the following output:

```
./Tools/src/checkstyle.sh
Run checkstyle script
Run 'gofmt'
Error: Found files not formatted by gofmt
/path/to/source/session-manager-plugin/src/log/log_unix.go
/path/to/source/session-manager-plugin/src/log/log_windows.go
/path/to/source/session-manager-plugin/src/sessionmanagerplugin/session/sessionutil/control_signals_unix.go
/path/to/source/session-manager-plugin/src/sessionmanagerplugin/session/sessionutil/control_signals_windows.go
/path/to/source/session-manager-plugin/src/sessionmanagerplugin/session/sessionutil/sessionutil_unix.go
/path/to/source/session-manager-plugin/src/sessionmanagerplugin/session/sessionutil/sessionutil_windows.go
/path/to/source/session-manager-plugin/src/sessionmanagerplugin/session/shellsession/shellsession_unix.go
/path/to/source/session-manager-plugin/src/sessionmanagerplugin/session/shellsession/shellsession_windows.go
Please run 'gofmt -w' for files listed.
```