set_blocksize(): switch to passing struct file *

block/bdev.c

block/ioctl.c

drivers/block/pktcdvd.c

fs/btrfs/dev-replace.c

fs/btrfs/volumes.c

fs/ext4/super.c

fs/reiserfs/journal.c

fs/xfs/xfs_buf.c

include/linux/blkdev.h