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@nobleSigned-off-by: NeilBrown <neilb@suse.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Maxim Levitsky <maximlevitsky@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/memstick/core/ms_block.c

@@ -2338,23 +2338,11 @@ 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;
 }
@@ -2362,7 +2350,6 @@ static int __init msb_init(void)
 static void __exit msb_exit(void)
 {
 	memstick_unregister_driver(&msb_driver);
-	unregister_blkdev(major, DRIVER_NAME);
 	idr_destroy(&msb_disk_idr);
 }