nan [was: grftest failure]

[Clint Adams]

> RCS file: /cvsroot/bogofilter/bogofilter/robinson.c,v
> retrieving revision 1.22.2.3
> diff -r1.22.2.3 robinson.c
> 220c220
> <         if (fabs(EVEN_ODDS - prob) >= min_dev) {
> ---
> >         if (fabs(EVEN_ODDS - prob) - min_dev >= EPS) {

With -O2, t.grftest passes, but make check fails at
../../../bogofilter/tests/t.systest.d/outputs/grftest.out
./checks.13437.20030105T135330/tests/grftest.out differ: byte 76, line 2