Currently, the churn state is printed only in sysfs. Add netlink support
so users could get the state via netlink.
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Link: https://patch.msgid.link/20260224020215.6012-1-liuhangbin@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>