net/smc: Fix lookup of netdev by using ib_device_get_netdev()

The SMC-R variant of the SMC protocol used direct call to function
ib_device_ops.get_netdev() to lookup netdev. As we used mlx5 device
driver to run SMC-R, it failed to find a device, because in mlx5_ib the
internal net device management for retrieving net devices was replaced
by a common interface ib_device_get_netdev() in commit 8d159eb2
("RDMA/mlx5: Use IB set_netdev and get_netdev functions").

Since such direct accesses to the internal net device management is not
recommended at all, update the SMC-R code to use proper API
ib_device_get_netdev().

Fixes: 54903572 ("net/smc: allow pnetid-less configuration")
Reported-by: Aswin K <aswin@linux.ibm.com>
Reviewed-by: Gerd Bayer <gbayer@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
Reviewed-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev>
Reviewed-by: D. Wythe <alibuda@linux.alibaba.com>
Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Link: https://patch.msgid.link/20241106082612.57803-1-wenjia@linux.ibm.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>