[CM] ffi unbound variable with use of discrete

[stephane boussuge]

hi,
it seem to have a bug in last version of grace (3.3.0) when i try the  
mapping example :
loop repeat 20
   for x = ran(1.0)
   for d = discrete(x, 0.0, 1.0, 48, 90)
   print "x=", x, " d=", d
end

i've a:
ffi_discrete: unbound variable>>> Error: ffi_discrete: unbound variable

cheers

stf