eal: fix service core list parsing
eal: fix service core list parsing

This patch adds checking for service core index validity when parsing
service corelist.

Fixes: 7dbd7a6413ef ("service: add -S corelist option")
Cc: stable@dpdk.org

Signed-off-by: Chengwen Feng <af69652d70a703aa3bb4268f61750255b6f8fb91@huawei.com>
Signed-off-by: Min Hu (Connor) <f02e10cb0a484c51b0f8634f83fbb4ab9ded1c6a@huawei.com>
Acked-by: Harry van Haaren <b9ad04ed670c22cfa7f5f9ab17e311ca85d11a76@intel.com>

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