RDMA/core: Remove unnecessary statements

The rdma_zalloc_drv_obj() in __ib_alloc_pd() would zero pd, it unnecessary
add NULL to the object in struct pd.

The uverbs_free_pd() already return busy if pd->usecnt is true, there is
no need to add a warning.

Link: https://lore.kernel.org/r/20220223074901.201506-1-yajun.deng@linux.devSigned-off-by: Yajun Deng <yajun.deng@linux.dev>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/core/verbs.c

@@ -268,9 +268,6 @@ struct ib_pd *__ib_alloc_pd(struct ib_device *device, unsigned int flags,
 		return ERR_PTR(-ENOMEM);
 
 	pd->device = device;
-	pd->uobject = NULL;
-	pd->__internal_mr = NULL;
-	atomic_set(&pd->usecnt, 0);
 	pd->flags = flags;
 
 	rdma_restrack_new(&pd->res, RDMA_RESTRACK_PD);
@@ -341,11 +338,6 @@ int ib_dealloc_pd_user(struct ib_pd *pd, struct ib_udata *udata)
 		pd->__internal_mr = NULL;
 	}
 
-	/* uverbs manipulates usecnt with proper locking, while the kabi
-	 * requires the caller to guarantee we can't race here.
-	 */
-	WARN_ON(atomic_read(&pd->usecnt));
-
 	ret = pd->device->ops.dealloc_pd(pd, udata);
 	if (ret)
 		return ret;