Tweak Solaris buildbot setup.

* tools/buildbot/slaves/svn-sparc-solaris/svnclean.sh: Rename to ...
* tools/buildbot/slaves/svn-sparc-solaris/svncleanup.sh: .. this.
* tools/buildbot/slaves/svn-sparc-solaris/svnenv.sh: Export on separate line.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1580855 13f79535-47bb-0310-9956-ffa450edef68