message: Fix a file_mac test case.
diff: @@ -107,8 +107,9 @@ echo "+++ Starting test $test_name..."
  MAC_OUTPUT_FILE="$TEST_TMPDIR/computed_mac_log.txt"
  ##### Run computation.
  -test_command $FILE_MAC_CLI $KEYSET_FILE $DATA_FILE --alsologtostderr 2> $MAC_OUTPUT_FILE
  -TEST_STATUS=$?
  +$FILE_MAC_CLI $KEYSET_FILE $DATA_FILE --alsologtostderr 2> $MAC_OUTPUT_FILE
  +##### Check that the correct MAC was produced in the logs
  +test_command grep --quiet --ignore-case "$CORRECT_MAC" "$MAC_OUTPUT_FILE"
  if [[ $TEST_STATUS -eq 0 ]]; then
  echo "+++ Success: MAC computation was successful."
  