[PATCH] html.c: die when write fails

[John Keeping]

On Sat, May 18, 2013 at 05:05:21PM +0200, Jason A. Donenfeld wrote:
> It seems reasonable to die like this. However, if we're going to start
> using git's die_errno, I'd also like to use that in other places
> instead of die().

Yeah, there are probably a lot of places that would be helped by this.
This was just the one I noticed when I mis-clicked and then clicked
again aborting the first request, which caused a spew of "html output
truncated" messages as CGit carried on generating the page.