2D probe output omits vel(2) and prints to stdout every step (s_write_probe_files)

[sbryngelson]

Summary

For a plain 2D case (no bubbles, no hypoelasticity) s_write_probe_files in src/simulation/m_data_output.fpp writes only (t, rho, vel(1), pres) to D/probe<i>_prim.dat — the second velocity component is dropped — and it also prints a line to stdout on every time step:

                    else
                        write (i + 30, '(6X,F12.6,F24.8,F24.8,F24.8)') nondim_time, rho, vel(1), pres
                        print *, 'time =', nondim_time, 'rho =', rho, 'pres =', pres
                    end if

(master 33ad77a6, the p == 0 branch). The 3D branch writes vel(1), vel(2), vel(3), and the 2D bubble and hypoelastic branches write vel(2) too, so this is just the plain-2D branch being incomplete. The print floods the job log (one line per step per probe) and looks like leftover debugging.

Reproducer

Any 2D case with probe_wrt = "T", e.g. examples/2D_ibm_airfoil with a probe added: the probe file has 4 columns and stdout gets time = ... rho = ... pres = ... every step.

Suggested fix

                     else
-                        write (i + 30, '(6X,F12.6,F24.8,F24.8,F24.8)') nondim_time, rho, vel(1), pres
-                        print *, 'time =', nondim_time, 'rho =', rho, 'pres =', pres
+                        #:if not MFC_CASE_OPTIMIZATION or num_dims > 1
+                            write (i + 30, '(6X,F12.6,F24.8,F24.8,F24.8,F24.8)') nondim_time, rho, vel(1), vel(2), pres
+                        #:endif
                     end if

(the fypp guard mirrors the neighbouring bubble/hypoelastic branches, since vel(2) does not exist under 1D case optimization). This changes the 2D probe file layout from 4 to 5 columns, so any golden probe files for 2D probe tests would need regenerating. Happy to PR.