(Reviewing r1485114)
Make antiLockingDocBase an absolute path.
It is very unlikely that java.io.tmpdir is not an absolute path. For consistency, convert it to the absolute form just once, so the path used when starting and stopping the webapp is certainly the same.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1488151 13f79535-47bb-0310-9956-ffa450edef68