RDMA/odp: remove ib_ucontext from ib_umem

At this point the ucontext is only being stored to access the ib_device,
so just store the ib_device directly instead. This is more natural and
logical as the umem has nothing to do with the ucontext.

Link: https://lore.kernel.org/r/20190806231548.25242-8-jgg@ziepe.ca
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
diff --git a/include/rdma/ib_umem.h b/include/rdma/ib_umem.h
index 1052d0d..a91b2af 100644
--- a/include/rdma/ib_umem.h
+++ b/include/rdma/ib_umem.h
@@ -42,7 +42,7 @@ struct ib_ucontext;
 struct ib_umem_odp;
 
 struct ib_umem {
-	struct ib_ucontext     *context;
+	struct ib_device       *ibdev;
 	struct mm_struct       *owning_mm;
 	size_t			length;
 	unsigned long		address;