vfio/mdev: unexport mdev_bus_type

mdev_bus_type is only used in mdev.ko now, so unexport it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Link: https://lore.kernel.org/r/20220923092652.100656-8-hch@lst.deSigned-off-by: Alex Williamson <alex.williamson@redhat.com>

drivers/vfio/mdev/mdev_driver.c

@@ -46,7 +46,6 @@ struct bus_type mdev_bus_type = {
 	.remove		= mdev_remove,
 	.match		= mdev_match,
 };
-EXPORT_SYMBOL_GPL(mdev_bus_type);
 
 /**
  * mdev_register_driver - register a new MDEV driver

drivers/vfio/mdev/mdev_private.h

@@ -13,6 +13,7 @@
 int  mdev_bus_register(void);
 void mdev_bus_unregister(void);
 
+extern struct bus_type mdev_bus_type;
 extern const struct attribute_group *mdev_device_groups[];
 
 #define to_mdev_type_attr(_attr)	\

include/linux/mdev.h

@@ -87,8 +87,6 @@ struct mdev_driver {
 	struct device_driver driver;
 };
 
-extern struct bus_type mdev_bus_type;
-
 int mdev_register_parent(struct mdev_parent *parent, struct device *dev,
 		struct mdev_driver *mdev_driver, struct mdev_type **types,
 		unsigned int nr_types);