remove the following VOPs.

	VOP_BLKATOFF
	VOP_VALLOC
	VOP_BALLOC
	VOP_REALLOCBLKS
	VOP_VFREE
	VOP_TRUNCATE
	VOP_UPDATE
regen.
#if 0 out code which abuses VOP_BALLOC.
adapt ufs.
adapt nfs.
adapt msdosfs.
adapt coda.
adapt ptyfs.
adapt portal.
adapt kernfs.
adapt specfs and fifofs.
adapt procfs.
adapt deadfs.
adapt fdesc.
adapt adosfs.
adapt cd9660.
adapt filecore.
adapt union.
adapt ntfs.
adapt tmpfs.