st/nine: handle integer support properly for CALLNZ

When the card supports native integers, the boolean
are stored in 32 bits int and are equal to
0 or 0xFFFFFFFF.

Given 0xFFFFFFFF is NaN if it was a float, better use
UIF than IF.

Signed-off-by: Axel Davy <axel.davy@ens.fr>