According to Julian initialising the previously uninitialised variable

According to Julian initialising the previously uninitialised variable
won't affect the test adversely -- so let's do this and get rid of
the special compilation again. Also guard against future compiler smartness
tricking the compiler into believing the variable is actually used.
So the loop won't get optimised away.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@14094