Added the "total" line, which makes it easy to answer questions like,
"how the hell much space am I wasting on /data/dalvik-cache?".
Also fixed the -s filename output, which was showing mostly-full paths
when a simple filename was called for.
This may not be useful, and may actually be misleading since yaffs2
doesn't track the blocks used for each file (it just divides the length
down by 512). I'm submitting it because yaffs2 isn't the only
filesystem we'll ever use.
I also changed some sprintf to snprintf, mostly out of paranoid habit.
Andy McFadden