crt: Fix the wording of a fallback #error in func.def.in

This was missed in 33d8fc4ce32fdc9fa1a0486c2f96f08252c6c841; we
no longer use DEF_<ARCH> defines, but rely on the compiler
built-in architecture defines.

Signed-off-by: Martin Storsjö <martin@martin.st>
1 file changed