memstick: don't allocate unused major for ms_block

When alloc_disk(0) is used the ->major number is completely ignored.
All devices are allocated with a major of BLOCK_EXT_MAJOR.

So remove registration and deregistration of 'major'.

Link: http://lkml.kernel.org/r/20160602064318.4403.49955.stgit@noble
Signed-off-by: NeilBrown <[email protected]>
Cc: Keith Busch <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Maxim Levitsky <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Author: NeilBrown

drivers/memstick/core/ms_block.c

@@ -2338,31 +2338,18 @@ static struct memstick_driver msb_driver = {
 	.resume   = msb_resume
 };
 
-static int major;
-
 static int __init msb_init(void)
 {
-	int rc = register_blkdev(0, DRIVER_NAME);
-
-	if (rc < 0) {
-		pr_err("failed to register major (error %d)\n", rc);
-		return rc;
-	}
-
-	major = rc;
-	rc = memstick_register_driver(&msb_driver);
-	if (rc) {
-		unregister_blkdev(major, DRIVER_NAME);
+	int rc = memstick_register_driver(&msb_driver);
+	if (rc)
 		pr_err("failed to register memstick driver (error %d)\n", rc);
-	}
 
 	return rc;
 }
 
 static void __exit msb_exit(void)
 {
 	memstick_unregister_driver(&msb_driver);
-	unregister_blkdev(major, DRIVER_NAME);
 	idr_destroy(&msb_disk_idr);
 }