ffffrw crashes due to missing Setup_DataArrays call

[wrp]

File: eval_f.c
Function: ffffrw_work

The ffffrw function (find first row matching expression) crashes
with a segfault because ffffrw_work does not call Setup_DataArrays
before using the data arrays. Compare with ffcrow_work which does
call Setup_DataArrays and works correctly.

Reproduction: Call ffffrw on a valid FITS file with a simple
expression like "COL1 > 0".