test/hash: init parameters in the correct function

test/hash: init parameters in the correct function

Each test case initializes its hash parameters in the test case
function. To be consistent, generate keys function should initialize
hash parameters similarly.

Fixes: c7eb0972e74b ("test/hash: add lock-free r/w concurrency")
Cc: stable@dpdk.org
Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Dharmik Thakkar <dharmik.thakkar@arm.com>