Fix re-creation of the pool directory

Whenever vip is deleted the complete pool directory
is deleted, but since pool is still alive the get_stats
function recreates the directory. The fix prevents the
re-creation of the directory. Respective unit test case
is also modified

Change-Id: I577e8e3a51db361210aa83a6c7f9b4f61210e924
Closes-Bug: #1317871
Merge "Fix re-creation of the pool directory"