hg: jdk9/sandbox/hotspot: Only attempt to archive log files if _stream is valid.

[marcus.larsson at oracle.com]

Changeset: 4557632aefd6
Author:    mlarsson
Date:      2015-09-04 13:09 +0200
URL:       http://hg.openjdk.java.net/jdk9/sandbox/hotspot/rev/4557632aefd6

Only attempt to archive log files if _stream is valid.
Add remove() call before rename since windows doesn't replace
existing files on calls to rename().

! src/share/vm/logging/logFileOutput.cpp