net: Return the correct errno code

[ Upstream commit 49251cd00228a3c983651f6bb2f33f6a0b8f152e ]

When kalloc or kmemdup failed, should return ENOMEM rather than ENOBUF.

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>