[t:2309] linux fix to windows port (export toku_dup2)

svn:ignore

git-svn-id: file:///svn/toku/tokudb@17021 c7de825b-a66e-492c-adef-691d508d4ae1

src/export.map

@@ -50,6 +50,7 @@
 
    toku_stat;
    toku_fstat;
+   toku_dup2;
 
  local: *;
 };