OpenMP, Fortran: Fix indentation in resolve_omp_clauses_aff_dep_map_cache

Commit basepoints/gcc-17-1747-ga7724fcb5f4 moved a large block of code
from resolve_omp_clauses to a new function.  I noticed that the
indentation of some nested switch statements looked odd when trying to
rebase some patches on top of this, and Tobias independently had
addressed this as part of his own WIP followup patch posted at
https://gcc.gnu.org/pipermail/gcc-patches/2026-June/721741.html.  This
patch addresses just the indentation problem and doesn't include any
functional changes.

gcc/fortran/ChangeLog
	* openmp.cc (resolve_omp_clauses_aff_dep_map_cache): Fix
	indentation.
Co-authored-by: Tobias Burnus <tburnus@baylibre.com>