Staging: hv: Use generic device_driver shutdown function

In preparation for moving all the state from struct driver_context
to struct hv_driver, eliminate the shutdown() function from
struct driver_context and use generic device_driver shutdown()
function.
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Abhishek Kane <v-abkane@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Hank Janssen <hjanssen@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/hv/blkvsc_drv.c

@@ -188,7 +188,7 @@ static int blkvsc_drv_init(int (*drv_init)(struct hv_driver *drv))
 
 	drv_ctx->driver.probe = blkvsc_probe;
 	drv_ctx->driver.remove = blkvsc_remove;
-	drv_ctx->shutdown = blkvsc_shutdown;
+	drv_ctx->driver.shutdown = blkvsc_shutdown;
 
 	/* The driver belongs to vmbus */
 	ret = vmbus_child_driver_register(drv_ctx);

drivers/staging/hv/vmbus_drv.c

@@ -1000,8 +1000,8 @@ static void vmbus_shutdown(struct device *child_device)
 	driver_ctx = driver_to_driver_context(child_device->driver);
 
 	/* Let the specific open-source driver handles the removal if it can */
-	if (driver_ctx->shutdown)
-		driver_ctx->shutdown(child_device);
+	if (driver_ctx->driver.shutdown)
+		driver_ctx->driver.shutdown(child_device);
 
 	return;
 }