Some drivers may return errcode when switch allmulticast mode,
so it's necessary to check the return code.
Fixes: b34801d1aa2e ("kni: support allmulticast mode set")
Cc: stable@dpdk.org
Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
Signed-off-by: Min Hu (Connor) <humin29@huawei.com>
Acked-by: Ferruh Yigit <ferruh.yigit@intel.com>