test/table: fix uninitialized parameter

test/table: fix uninitialized parameter

delete_bulk() copies metadata to pointers provided by the entries
parameter, but in the unit test, they are uninitialized, leading
to rte_table attempting to memcpy into random garbage pointers.

Memsetting pointer table to zero will prevent that from happening.

Fixes: 48f2543cf0a8 ("app/test: add bulk adding and deleting")
Cc: stable@dpdk.org
Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Acked-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>