udev: re-read the discovery log page when a discovery controller reconnected

udev: re-read the discovery log page when a discovery controller reconnected

When using persistent discovery controllers, if the discovery
controller loses connectivity and manage to reconnect after a while,
we need to retrieve again the discovery log page in order to learn
about possible changes that may have occurred during this time as
discovery log change events were lost.

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Link: https://lore.kernel.org/r/20220627080650.108936-1-sagi@grimberg.me