Workaround for Linux bug: return post_op_attr for NFS-RDMA READ3

Linux NFS RDMA transport has a stupid bug - when the reply doesn't contain
post_op_attr, the data gets offsetted by 84 bytes (size of attributes) and
first 84 bytes are filled with probably random data.

src/nfs/nfs_kv_remove.cpp

@@ -197,7 +197,7 @@ resume_5:
         auto copy = st->ientry.object_items();
         copy["nlink"] = st->ientry["nlink"].uint64_value()-1;
         copy["ctime"] = nfstime_now_str();
-        st->self->parent->db->set(kv_inode_key(st->ino), json11::Json(copy).dump(), [st](int res)
+        st->self->parent->kvfs->write_inode(st->ino, copy, false, [st](int res)
         {
             st->res = res;
             nfs_kv_continue_delete(st, 6);