IB/core: Replace ib_umem's offset field with a full address

In order to allow umems that do not pin memory, we need the umem to
keep track of its region's address.

This makes the offset field redundant, and so this patch removes it.

Signed-off-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

drivers/infiniband/hw/ocrdma/ocrdma_verbs.c

@@ -805,7 +805,7 @@ struct ib_mr *ocrdma_reg_user_mr(struct ib_pd *ibpd, u64 start, u64 len,
 		goto umem_err;
 
 	mr->hwmr.pbe_size = mr->umem->page_size;
-	mr->hwmr.fbo = mr->umem->offset;
+	mr->hwmr.fbo = ib_umem_offset(mr->umem);
 	mr->hwmr.va = usr_addr;
 	mr->hwmr.len = len;
 	mr->hwmr.remote_wr = (acc & IB_ACCESS_REMOTE_WRITE) ? 1 : 0;