net/mlx5: Reset mkey index on creation

stable inclusion
from stable-5.10.46
commit 327e626c39f3e152b0306b41708a51a5d471c165
bugzilla: 168323
CVE: NA

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

[ Upstream commit 0232fc2d ]

Reset only the index part of the mkey and keep the variant part. On
devlink reload, driver recreates mkeys, so the mkey index may change.
Trying to preserve the variant part of the mkey, driver mistakenly
merged the mkey index with current value. In case of a devlink reload,
current value of index part is dirty, so the index may be corrupted.

Fixes: 54c62e13 ("{IB,net}/mlx5: Setup mkey variant before mr create command invocation")
Signed-off-by: Aya Levin <ayal@nvidia.com>
Signed-off-by: Amir Tzin <amirtz@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
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>