hsr: add restart routine into hsr_get_node_list()

[ Upstream commit ca19c70f ]

The hsr_get_node_list() is to send node addresses to the userspace.
If there are so many nodes, it could fail because of buffer size.
In order to avoid this failure, the restart routine is added.

Fixes: f421436a

 ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>