[rfa/testsuite] Don't display values in output of pc-fp.exp

[Andrew Cagney]

> 
> That's a good point; I hadn't thought of that.  I'm actually not
> entirely sure what it is that leads to the value of $fp changing from
> test run to test run.  But I will make the empirical observation that
> it does change from test run to test run, and I'd be shocked if those
> changes reflected introduction of new bugs into GDB.

Hmm, from memory, $fp, is affected by your environment. environ[] is 
pushed onto the stack before calling main.

Andrew