Fix an intermittent failure in "tool flushing test"

The test (MatrixTranspose) and the tracer tool both write to stdout
which sometime causes a trace corruption.

Change the test to emit info messages to stderr instead of stdout,
leaving stdout for the tracer tool's exclusive use.

Change-Id: I18047dbcd9039b70dd24ef6e7e8e9d89b40bedd2

test/run.sh

@@ -80,7 +80,7 @@ eval_test() {
     echo "test $test_number: $test_name \"$label\""
     echo "CMD: \"$cmdline\""
     test_runnum=$((test_runnum + 1))
-    eval "$cmdline" >$test_trace 2>&1
+    eval "$cmdline" 1>$test_trace 2>$test_name.err
     is_failed=$?
     if [ $is_failed != 0 ] ; then
       cat $test_trace