bcachefs: Fix rcu_read_lock() leak in drop_extra_replicas

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/data_update.c

@@ -202,9 +202,8 @@ static int __bch2_data_update_index_update(struct btree_trans *trans,
 			bch2_bkey_durability(c, bkey_i_to_s_c(&new->k_i));
 
 		/* Now, drop excess replicas: */
-restart_drop_extra_replicas:
-
 		rcu_read_lock();
+restart_drop_extra_replicas:
 		bkey_for_each_ptr_decode(old.k, bch2_bkey_ptrs(bkey_i_to_s(insert)), p, entry) {
 			unsigned ptr_durability = bch2_extent_ptr_durability(c, &p);