close[t:4602] Make gcc 4.6.2 stop complaining about valgrind 3.6.1 {{{unused-but-set-variable}}} warnings ({{{svn merge -c 40646 ../tokudb.4594/}}}. Closes #4602.

git-svn-id: file:///svn/toku/tokudb@40647 c7de825b-a66e-492c-adef-691d508d4ae1