service: fix lcore role after delete

service: fix lcore role after delete

This patch fixes the reset of the service core,
that when rte_service_lcore_del() is called, the
lcore_role is restored to RTE.

This issue was reported as when running the unit tests, an
error was thrown that "failed to allocate lcore". Investigating
revealed that the state of the service-cores after del() was
not allowing a core to be re-used at a later point in time.

Fixes: 21698354c832 ("service: introduce service cores concept")
Cc: stable@dpdk.org
Reported-by: Pavan Nikhilesh <pbhagavatula@caviumnetworks.com>
Signed-off-by: Harry van Haaren <harry.van.haaren@intel.com>
Acked-by: Pavan Nikhilesh <pbhagavatula@caviumnetworks.com>