mempool: fix local cache initialization
mempool: fix local cache initialization

The mempool local cache was not initialized properly leading to
undefined behavior in cases where the allocated memory was used
previously and left with data.

Fixes: 213af31e0960 ("mempool: reduce structure size if no cache needed")

Signed-off-by: Sergio Gonzalez Monroy <efb28dd1236fe58fb57f933212eddfe89b9da704@intel.com>
Acked-by: Olivier Matz <dfcc1510895413197abb4336e39bb0a3906cba71@6wind.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk