spmi: do not use bus internal data

The variable p is a data structure which is used by the driver core
internally and it is not expected that busses will be directly accessing
these driver core internal only data.

Signed-off-by: Sudip Mukherjee <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/spmi/spmi.c

···
 #define CREATE_TRACE_POINTS
 #include <trace/events/spmi.h>
 
+static bool is_registered;
 static DEFINE_IDA(ctrl_ida);
 
 static void spmi_dev_release(struct device *dev)
···
 	int ret;
 
 	/* Can't register until after driver model init */
-	if (WARN_ON(!spmi_bus_type.p))
+	if (WARN_ON(!is_registered))
 		return -EAGAIN;
 
 	ret = device_add(&ctrl->dev);
···
 
 static int __init spmi_init(void)
 {
-	return bus_register(&spmi_bus_type);
+	int ret;
+
+	ret = bus_register(&spmi_bus_type);
+	if (ret)
+		return ret;
+
+	is_registered = true;
+	return 0;
 }
 postcore_initcall(spmi_init);