driver-core: constify data for class_find_device()

All in-kernel users of class_find_device() don't really need mutable
data for match callback.

In two places (kernel/power/suspend_test.c, drivers/scsi/osd/osd_uld.c)
this patch changes match callbacks to use const search data.

The const is propagated to rtc_class_open() and power_supply_get_by_name()
parameters.

Note that there's a dev reference leak in suspend_test.c that's not
touched in this patch.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/linux/device.h b/include/linux/device.h
index 251f33b..a089676 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -395,8 +395,8 @@
 				 void *data,
 				 int (*fn)(struct device *dev, void *data));
 extern struct device *class_find_device(struct class *class,
-					struct device *start, void *data,
-					int (*match)(struct device *, void *));
+					struct device *start, const void *data,
+					int (*match)(struct device *, const void *));
 
 struct class_attribute {
 	struct attribute attr;