block: unexport get_gendisk

get_gendisk is not used by any modular code.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

block/genhd.c

@@ -980,7 +980,6 @@ struct gendisk *get_gendisk(dev_t devt, int *partno)
 	}
 	return disk;
 }
-EXPORT_SYMBOL(get_gendisk);
 
 /**
  * bdget_disk - do bdget() by gendisk and partition number