test/hash: use C11 atomics in lock-free perf test

test/hash: use C11 atomics in lock-free perf test

Replace rte_atomic APIs with C11 atomic APIs in
test_hash_readwrite_lf_perf.c

Signed-off-by: Dharmik Thakkar <dharmik.thakkar@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Acked-by: Yipeng Wang <yipeng1.wang@intel.com>