parisc: make parisc_bus_type const

Since commit d492cc25 ("driver core: device.h: make struct
bus_type a const *"), the driver core can properly handle constant
struct bus_type, move the parisc_bus_type variable to be a constant
structure as well, placing it into read-only memory which can not be
modified at runtime.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Helge Deller <deller@gmx.de>

arch/parisc/include/asm/parisc-device.h

@@ -61,7 +61,7 @@ parisc_get_drvdata(struct parisc_device *d)
 	return dev_get_drvdata(&d->dev);
 }
 
-extern struct bus_type parisc_bus_type;
+extern const struct bus_type parisc_bus_type;
 
 int iosapic_serial_irq(struct parisc_device *dev);
 

arch/parisc/kernel/drivers.c

@@ -618,7 +618,7 @@ static struct attribute *parisc_device_attrs[] = {
 };
 ATTRIBUTE_GROUPS(parisc_device);
 
-struct bus_type parisc_bus_type = {
+const struct bus_type parisc_bus_type = {
 	.name = "parisc",
 	.match = parisc_generic_match,
 	.uevent = parisc_uevent,