Fix tmpdir usage in heap-profiler_unittest.sh
Fix tmpdir usage in heap-profiler_unittest.sh

Using a single fixed directory would break when tests were being run in
parallel with "make -jN".

Also, the cleanup at the end of the test didn't work because it referred
to the wrong variable.

chencl/gperftools,alk/gperftools,acmorrow/gperftools,acmorrow/gperftools,gshirishfree/gperftools,romange/gperftools,gshirishfree/gperftools,gshirishfree/gperftools,chencl/gperftools,gshirishfree/gperftools,rzinsly/gperftools,xiaoyur347/gperftools,gperftools/gperftools,gperftools/gperftools,alk/gperftools,romange/gperftools,chencl/gperftools,rzinsly/gperftools,alk/gperftools,rzinsly/gperftools,acmorrow/gperftools,romange/gperftools,xiaoyur347/gperftools,gperftools/gperftools,xiaoyur347/gperftools,xiaoyur347/gperftools,acmorrow/gperftools,romange/gperftools,rzinsly/gperftools,gperftools/gperftools,alk/gperftools,chencl/gperftools