KVM test: rss.cpp: use critical section instead of mutex for text buffer access

A critical section should be faster.  The difference for this application may
or may not be noticeable (with a large number of files).

Signed-off-by: Michael Goldish <mgoldish@redhat.com>


git-svn-id: http://test.kernel.org/svn/autotest/trunk@4717 592f7852-d20e-0410-864c-8624ca9c26a4
2 files changed