[Patch, fortran] Fix PR fortran/50050 breakage: ICE on valid with null pointer initialization

[Thomas Koenig]

Hi Tobias,

> PPS: I am looking for someone to review my simple regression fix [4.3 to
> 4.7] at
> http://gcc.gnu.org/ml/fortran/2011-08/msg00186.html
> it *should* be safe - see last comment in the PR for a bit more context.

That one is OK.

Thanks!

	Thomas