Fortran: fix regression introduced by commit r16-914-g787a8dec1acedf

A last-minute cleanup before patch submission reordered a change
that should not have happened.  This fixes it.

	PR fortran/101735

gcc/fortran/ChangeLog:

	* primary.cc (gfc_match_varspec): Correct order of logic.

(cherry picked from commit 74a2281ae18c6dbbc640f0c79f7138a495ef8f0c)