kkolinko review
Use finishResponse() rather than flushBuffer to avoid chunking if not necessary.
Add finishResponse() to ErrorReportValve.report()
Don;t try and reset the response if it has already been marked as in error

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1600965 13f79535-47bb-0310-9956-ffa450edef68