Split tools/diag/prtblknos into two parts:

Split tools/diag/prtblknos into two parts:
	main.c - opens disk and processes the argument list
		 of inodes to be printed
	prtblknos.c - prints out the list of blocks used by an inode

This change allows the fsdb program to import prtblknos() to use when
printing out the set of blocks used by an inode.

This program was switched to using the libufs library to ease its
integration with fsdb and any other filesystem utility that might
want to use it in the future.