RDMA/umem: Use ib_dma_max_seg_size instead of dma_get_max_seg_size

RDMA ULPs must not call DMA mapping APIs directly but instead use the
ib_dma_* wrappers.

Fixes: 0c16d963 ("RDMA/umem: Move to allocate SG table from pages")
Link: https://lore.kernel.org/r/20201106181941.1878556-3-hch@lst.deReported-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/core/umem.c

@@ -229,10 +229,10 @@ struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr,
 
 		cur_base += ret * PAGE_SIZE;
 		npages -= ret;
-		sg = __sg_alloc_table_from_pages(
-			&umem->sg_head, page_list, ret, 0, ret << PAGE_SHIFT,
-			dma_get_max_seg_size(device->dma_device), sg, npages,
-			GFP_KERNEL);
+		sg = __sg_alloc_table_from_pages(&umem->sg_head, page_list, ret,
+				0, ret << PAGE_SHIFT,
+				ib_dma_max_seg_size(device), sg, npages,
+				GFP_KERNEL);
 		umem->sg_nents = umem->sg_head.nents;
 		if (IS_ERR(sg)) {
 			unpin_user_pages_dirty_lock(page_list, ret, 0);