[gfortran, PING] Fix function declaration syntax

[Paul Thomas]

Tobi,

>PING:
>http://gcc.gnu.org/ml/fortran/2005-12/msg00495.html
>
>Too bad I only noticed that the patch had not yet been committed, after I ran
>svn revert.
>  
>
That's because the original message did not look like a submission, nor 
did it go to the patch queue.

It's OK to commit, with two remarks:

(i) Obviously, pr23373-2.f90 must be corrected.
(ii) In the longer term we should add a test case that tests all the 
requirements and constraints of procedure declarations, if such a thing 
does not already exist.

Paul