vidforward: global logger returns underlying logger

The globalLogger type wraps a logger.Logger. If you use GetLogger
which gets the global logger (which provides an interface
logger.Logger) a type assertion to JSONLogger will fail, because
the type is actually globalLogger. We need to provide the
underlying logger instead when we return from GetLogger.

cmd/vidforward/global/logger.go

@@ -51,5 +51,6 @@ func GetLogger() logging.Logger {
 	if logger == nil {
 		panic("attempted get of uninstantiated global logger")
 	}
-	return logger
+	// We want to return the underlying logger.
+	return logger.Logger
 }