raw/skeleton: add missing check after setting attribute
raw/skeleton: add missing check after setting attribute

This patch adds return value check for setting an attribute.

Fixes: 88a81bcecb7b ("raw/skeleton: remove compile-time constant for device id")
Cc: stable@dpdk.org

Signed-off-by: Min Hu (Connor) <f02e10cb0a484c51b0f8634f83fbb4ab9ded1c6a@huawei.com>

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