Add a missing prof_alloc_rollback() call.
Add a missing prof_alloc_rollback() call.

In the case where prof_alloc_prep() is called with an over-estimate of
allocation size, and sampling doesn't end up being triggered, the tctx
must be discarded.

jemalloc/jemalloc-cmake,jemalloc/jemalloc-cmake,jemalloc/jemalloc-cmake,jemalloc/jemalloc-cmake