RDMA/uverbs: Track dmabuf memory regions

The dmabuf memory registrations are missing the restrack handling and
hence do not appear in rdma tool.

Fixes: bfe0cc6e ("RDMA/uverbs: Add uverbs command for dma-buf based MR registration")
Link: https://lore.kernel.org/r/20210812135607.6228-1-galpress@amazon.comSigned-off-by: Gal Pressman <galpress@amazon.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/core/uverbs_std_types_mr.c

@@ -249,6 +249,9 @@ static int UVERBS_HANDLER(UVERBS_METHOD_REG_DMABUF_MR)(
 	mr->uobject = uobj;
 	atomic_inc(&pd->usecnt);
 
+	rdma_restrack_new(&mr->res, RDMA_RESTRACK_MR);
+	rdma_restrack_set_name(&mr->res, NULL);
+	rdma_restrack_add(&mr->res);
 	uobj->object = mr;
 
 	uverbs_finalize_uobj_create(attrs, UVERBS_ATTR_REG_DMABUF_MR_HANDLE);