mips pipe.S cleanup

[sjhill at realitydiluted.com]

> > My testcase is:
> 
> should see about automating this and adding it to our test suite ...
>
Should this be a general test or an architecture specific one? Also,
I am in the process of a massive merge from trunk into the NPTL branch.
When I finish, I will work on pipe.S, again, and run the test. Someone
assign the bug to me in the bug tracking system.

-Steve