You need to add your current user in the HDFS core-site as proxyuser. Add the following configuration in the HADOOP_HOME/conf/core-site.xml:
In the above replace current_user with the desired user name value and replace host_name_server_running with the name of your server.
Essentially, the user who is running the oozie server process should be added as the proxy user in the core-site.xml. In your case, it happens to be the same user.