Temporal fix of dmtcp_get_tmpdir. Thread safety still nessesary.



git-svn-id: svn://svn.code.sf.net/p/dmtcp/code/trunk@2644 ba6dc0ae-232f-0410-883f-9ebac64fc565
Fix DMTCP tmpdir acquiring. Do not use UniquePid class directly.



git-svn-id: svn://svn.code.sf.net/p/dmtcp/code/trunk@2645 ba6dc0ae-232f-0410-883f-9ebac64fc565