Input: synaptics-rmi4 - fix use after free in rmi_unregister_function()

The put_device() calls rmi_release_function() which frees "fn" so the
dereference on the next line "fn->num_of_irqs" is a use after free.
Move the put_device() to the end to fix this.

Fixes: 24d28e4 ("Input: synaptics-rmi4 - convert irq distribution to irq_domain")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/706efd36-7561-42f3-adfa-dd1d0bd4f5a1@moroto.mountain
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Author: Dan Carpenter

drivers/input/rmi4/rmi_bus.c

@@ -277,11 +277,11 @@ void rmi_unregister_function(struct rmi_function *fn)
 
 	device_del(&fn->dev);
 	of_node_put(fn->dev.of_node);
-	put_device(&fn->dev);
 
 	for (i = 0; i < fn->num_of_irqs; i++)
 		irq_dispose_mapping(fn->irq[i]);
 
+	put_device(&fn->dev);
 }
 
 /**