net: wan: fix error return code of uhdlc_init()

stable inclusion
from stable-5.10.27
commit e6946ef438487695fd273294af2375c13e1b3a54
bugzilla: 51493

--------------------------------

[ Upstream commit 62765d39 ]

When priv->rx_skbuff or priv->tx_skbuff is NULL, no error return code of
uhdlc_init() is assigned.
To fix this bug, ret is assigned with -ENOMEM in these cases.

Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Acked-by:   Weilong Chen <chenweilong@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>