net/mlx5: Fix crash during sync firmware reset

stable inclusion
from stable-v5.10.153
commit fdba224ab02873a2998acf9d11ae5ac9a1e35717
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I64YCA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=fdba224ab02873a2998acf9d11ae5ac9a1e35717



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[ Upstream commit aefb62a9 ]

When setting Bluefield to DPU NIC mode using mlxconfig tool +  sync
firmware reset flow, we run into scenario where the host was not
eswitch manager at the time of mlx5 driver load but becomes eswitch manager
after the sync firmware reset flow. This results in null pointer
access of mpfs structure during mac filter add. This change prevents null
pointer access but mpfs table entries will not be added.

Fixes: 5ec69744 ("net/mlx5: Add support for devlink reload action fw activate")
Signed-off-by: Suresh Devarakonda <ramad@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Reviewed-by: Bodong Wang <bodong@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Link: https://lore.kernel.org/r/20221026135153.154807-12-saeed@kernel.org


Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Lipeng Sang <sanglipeng1@jd.com>