arguments for mkfs are not properly ordered

[xiaobin]

line 356 of bin/disk-image-create:

sudo mkfs $MKFS_OPTS -t $FS_TYPE -L ${DIB_ROOT_LABEL} ${IMAGE_BLOCK_DEVICE}

This works fine for extn fs, for example:
sudo mkfs -j -t ext4 /dev/loop0

but not good for xfs:

sudo mkfs -b size=4096 -t xfs /dev/nbd0

error:
mkfs.ext2: invalid block size - size=4096

moving -t xfs ahead of -b would work.
sudo mkfs -t xfs -b size=4096 /dev/nbd0

So suggest change it to:
mkfs -t $FS_TYPE $MKFS_OPTS -L ${DIB_ROOT_LABEL} ${IMAGE_BLOCK_DEVICE}