test/func_reentrancy: free memzones after test

test/func_reentrancy: free memzones after test

Function reentrancy test limits maximum number of iterations
simultaneously, however it doesn't free the 'fr_test_once'
memzones after the fact, so introduce freeing 'fr_test_once'
in ring/mempool/hash/fbk/lpm_clean.

Meanwhile, add the missing free for test case on main thread.

Fixes: 104a92bd026f ("app: add reentrancy tests")
Fixes: 995eec619024 ("test: clean up memory for function reentrancy test")
Cc: stable@dpdk.org
Signed-off-by: Joyce Kong <joyce.kong@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Reviewed-by: Feifei Wang <feifei.wang2@arm.com>
Reviewed-by: Olivier Matz <olivier.matz@6wind.com>
Acked-by: David Marchand <david.marchand@redhat.com>