Although this is not fixing any existing double free bug, making these
functions idempotent allows for a simpler implementation of future ndo
hooks that act on a single queue.
Tested-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Praveen Kaligineedi <pkaligineedi@google.com> Reviewed-by: Harshitha Ramamurthy <hramamurthy@google.com> Signed-off-by: Shailend Chand <shailend@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>