We do not garantee zero-ed memory for apr_skiplist_alloc(), neither in
the description, nor in the code for reused chunks.

So always allocate raw memory and don't rely on zero-ed one after internal
calls to apr_skiplist_alloc().


git-svn-id: https://svn.apache.org/repos/asf/apr/apr/trunk@1611107 13f79535-47bb-0310-9956-ffa450edef68