net/netlink: Redesign the logic that handles notifications of when response data is available. Signal handlers are sub-optimal inside the OS (especially after the preceding change which forces the hand). Instead, use the work queue notifiers as is done with all other network notifiers.

net/netdev/netdev.h

@@ -501,9 +501,9 @@ int netdev_ipv6_ifconf(FAR struct lifconf *lifc);
  * Name: netdown_notifier_setup
  *
  * Description:
- *   Set up to perform a callback to the worker function the network goes
- *   down.  The worker function will execute on the high priority worker
- *   thread.
+ *   Set up to perform a callback to the worker function when the network
+ *   goes down.  The worker function will execute on the high priority
+ *   worker thread.
  *
  * Input Parameters:
  *   worker - The worker function to execute on the high priority work

net/netdev/netdown_notifier.c

@@ -58,9 +58,9 @@
  * Name: netdown_notifier_setup
  *
  * Description:
- *   Set up to perform a callback to the worker function the network goes
- *   down.  The worker function will execute on the low priority worker
- *   thread.
+ *   Set up to perform a callback to the worker function when the network
+ *   goes down.  The worker function will execute on the high priority
+ *   worker thread.
  *
  * Input Parameters:
  *   worker - The worker function to execute on the low priority work