test/distributor: fix return type of thread function
test/distributor: fix return type of thread function

New warning with gcc 8.1:
When casting the function pointer passed to
rte_eal_remote_launch() as an lcore_function_t *,
it expects the cast function to return an int, but
instead it was returning void. Fixed to return
an int.

Fixes: c3eabff124e6 ("distributor: add unit tests")
Cc: stable@dpdk.org

Signed-off-by: David Hunt <763be7c8e0ad91e03160e7aed76d5cd41534e2f9@intel.com>
Acked-by: Pablo de Lara <28355d9cfe41bb8148aea0fb24f47aae8f4217a1@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk