Fix XFA FormCalc corpus test

This CL fixes the Oneof test based on the description in the txt file.
The third test will be suppressed because it outputs the wrong number
on the fourth text field: it should output 1 instead of 0.

BUG= pdfium:781

Change-Id: I8b63c1e15dfeb6cf0f7bcdf0b4b6e32f87d0279f
Reviewed-on: https://pdfium-review.googlesource.com/6838
Reviewed-by: dsinclair <dsinclair@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
11 files changed