reset: bail if try_module_get() fails

Abort instead of returning a new reset control for a reset controller
device that is going to have its module unloaded.

Reported-by: Uwe Kleine-König <[e-mail]>
Fixes: 61fc41317666 ("reset: Add reset controller API")
Acked-by: Uwe Kleine-König <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Philipp Zabel <[e-mail]>

drivers/reset/core.c

···
 	if (!rstc)
 		return ERR_PTR(-ENOMEM);
 
-	try_module_get(rcdev->owner);
+	if (!try_module_get(rcdev->owner)) {
+		kfree(rstc);
+		return ERR_PTR(-ENODEV);
+	}
 
 	rstc->rcdev = rcdev;
 	list_add(&rstc->list, &rcdev->reset_control_head);