RDMA/mlx5: Avoid flexible array warning

The following warning is reported by sparse tool:
drivers/infiniband/hw/mlx5/fs.c:1664:26: warning: array of flexible
structures

Avoid it by simply splitting array into two separate structs.

Link: https://patch.msgid.link/7b891b96a9fc053d01284c184d25ae98d35db2d4.1747827041.git.leon@kernel.org


Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>