driver core: Use system_percpu_wq instead of system_wq

Commit 1137838 ("driver core: Use mod_delayed_work to prevent lost
deferred probe work") added a use of system_wq, which is deprecated in
favor of system_percpu_wq added by commit 128ea9f ("workqueue: Add
system_percpu_wq and system_dfl_wq"). An upcoming warning in the
workqueue tree flags this with:

  workqueue: work func deferred_probe_timeout_work_func enqueued on deprecated workqueue. Use system_{percpu|dfl}_wq instead.

Switch to system_percpu_wq to clear up the warning.

Fixes: 1137838 ("driver core: Use mod_delayed_work to prevent lost deferred probe work")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>
Link: https://patch.msgid.link/20260601-driver-core-fix-system_wq-warning-v1-1-f9001a70ee25@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

Author: nathanchance

drivers/base/dd.c

@@ -324,7 +324,7 @@ void deferred_probe_extend_timeout(void)
 	 * start a new one.
 	 */
 	if (delayed_work_pending(&deferred_probe_timeout_work) &&
-	    mod_delayed_work(system_wq, &deferred_probe_timeout_work,
+	    mod_delayed_work(system_percpu_wq, &deferred_probe_timeout_work,
 			     secs_to_jiffies(driver_deferred_probe_timeout)))
 		pr_debug("Extended deferred probe timeout by %d secs\n",
 					driver_deferred_probe_timeout);