Small list fix

[Paolo Carlini]

Chris Jefferson wrote:

> Sorry if I misunderstood, but in a previous submission I was told not 
> to write "--end()".

"I was told" or "I was explained"?!?

    http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#355

> However I wondered across a couple of occurances of this very thing in 
> stl_list.h!

Where, given our implementation (and most of the others, at variance 
with the vector case!), is perfectly safe: indeed, it compiles, so...

> A very simple patch, bootstrapped and tests, and produces identical 
> output on -O2 to the old version.

... but I agree that, for consistency, we should apply your patchlet. 
Will do later today, if nobody objects.

Thanks,
Paolo.