mm/hmm: Do not use list*_rcu() for hmm->ranges

This list is always read and written while holding hmm->lock so there is
no need for the confusing _rcu annotations.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Jérôme Glisse <jglisse@redhat.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Ira Weiny <iweiny@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Philip Yang <Philip.Yang@amd.com>

mm/hmm.c

@@ -912,7 +912,7 @@ int hmm_range_register(struct hmm_range *range,
 
 	range->hmm = hmm;
 	kref_get(&hmm->kref);
-	list_add_rcu(&range->list, &hmm->ranges);
+	list_add(&range->list, &hmm->ranges);
 
 	/*
 	 * If there are any concurrent notifiers we have to wait for them for
@@ -942,7 +942,7 @@ void hmm_range_unregister(struct hmm_range *range)
 		return;
 
 	mutex_lock(&hmm->lock);
-	list_del_rcu(&range->list);
+	list_del(&range->list);
 	mutex_unlock(&hmm->lock);
 
 	/* Drop reference taken by hmm_range_register() */