Incorrect comments in log.hpp

https://github.com/openjdk/jdk/blob/622f72bc8b8a545deea065475d4bd556b87b681c/src/hotspot/share/logging/log.hpp#L75

The methods Log::debug_stream() and LogTarget::stream() do not exist.

// Example usage:
// Log(logging) log;
// if (log.is_debug()) {
// ...
// log.debug("result = %d", result).trace(" tracing info");
// obj->print_on(log.debug_stream());
// }

// Example usage:
// LogTarget(Debug, gc) out;
// if (out.is_enabled()) {
// ...
// out.print("Worker: %u", i);
// out.print(" data: %d", x);
// ...
// print_stats(out.stream());
// }