unetmsg: fix inverted condition in network_rx_socket_close()

unetmsg: fix inverted condition in network_rx_socket_close()

The cleanup condition checked != instead of ==, inverting the logic.
This caused two problems:

When an authenticated RX connection disconnected, remote state for that
host was never cleaned up since the stored entry matched the one being
closed.

When a stale unauthenticated connection from a peer closed, any existing
authenticated connection from the same peer was incorrectly deleted and
its remote state wiped.

Signed-off-by: Felix Fietkau <nbd@nbd.name>