run_remote_tests: fix bug where new symlink got created instead of update

run_remote_tests.sh

 #!/bin/bash
 
 # Copyright (c) 2009 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # Script to run client or server tests on a live remote image.
 
 # Load common constants.  This should be the first executable line.
 # The path to common.sh should be relative to your script's location.
@@ skipping 61 matching lines @@
   ssh-add $tmp_private_key
 }
 
 function cleanup() {
   # Always remove the build path in case it was used.
   [[ -n "${BUILD_DIR}" ]] && sudo rm -rf "${BUILD_DIR}"
   if [[ $FLAGS_cleanup -eq ${FLAGS_TRUE} ]] || \
      [[ ${RAN_ANY_TESTS} -eq ${FLAGS_FALSE} ]]; then
     rm -rf "${TMP}"
   else
-    ln -sf "${TMP}" /tmp/run_remote_tests.latest
+    ln -nsf "${TMP}" /tmp/run_remote_tests.latest
     echo ">>> Details stored under ${TMP}"
   fi
   stop_ssh_agent
   cleanup_remote_access
 }
 
 # Determine if a control is for a client or server test.  Echos
 # either "server" or "client".
 # Arguments:
 #   $1 - control file path
@@ skipping 240 matching lines @@
 
   echo ""
   info "Test results:"
   ./generate_test_report "${TMP}" --strip="${TMP}/"
 
   print_time_elapsed
 }
 
 restart_in_chroot_if_needed "$@"
 main "$@"