[patch] Fix typo for libffi library version

[Paolo Bonzini]

Matthias Klose wrote:
> Set the libffi library version according to
> http://gcc.gnu.org/ml/gcc/2004-06/msg00784.html. Commited as obvious.
 >
> -4:0:1
> +4:1:0

Nope, 4:0:1 was ok.  There's actually no ABI change between the old 
release-numbered 3.x and the new 4:0, so the AGE must be 1.

Paolo