IB/mlx5: Declare local functions 'static'

This patch avoids that sparse complains about missing function
declarations.

Fixes: c9990ab ("RDMA/umem: Move all the ODP related stuff out of ucontext and into per_mm")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/mlx5/odp.c

@@ -101,7 +101,7 @@ static int check_parent(struct ib_umem_odp *odp,
 	return mr && mr->parent == parent && !odp->dying;
 }
 
-struct ib_ucontext_per_mm *mr_to_per_mm(struct mlx5_ib_mr *mr)
+static struct ib_ucontext_per_mm *mr_to_per_mm(struct mlx5_ib_mr *mr)
 {
 	if (WARN_ON(!mr || !is_odp_mr(mr)))
 		return NULL;