test/hash: fix perf result

test/hash: fix perf result

Reset 'iter' and 'tbl_rw_test_param.found' on each iteration
to give correct result for lost and duplicated keys.

This patch also changes the default return value of the test to -1
when not enough resources are provided.

Fixes: 0eb3726ebcf14 ("test/hash: add test for read/write concurrency")
Cc: stable@dpdk.org
Signed-off-by: Dharmik Thakkar <dharmik.thakkar@arm.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>
Reviewed-by: Yipeng Wang <yipeng1.wang@intel.com>