Philippe 02/01/2023: FLAT_INVZ: use GET_HALO_DDC for PF_1_Y

This fixes problems with convergence of solver (on CPU and GPU)

src/MNH/flat_invz.f90

-!MNH_LIC Copyright 1994-2022 CNRS, Meteo-France and Universite Paul Sabatier
+!MNH_LIC Copyright 1994-2023 CNRS, Meteo-France and Universite Paul Sabatier
 !MNH_LIC This is part of the Meso-NH software governed by the CeCILL-C licence
 !MNH_LIC version 1. See LICENSE, CeCILL-C_V1-en.txt and CeCILL-C_V1-fr.txt
 !MNH_LIC for details. version 1.
@@ -1140,7 +1140,7 @@ CALL PRINT_MSG( NVERB_WARNING, 'GEN', 'FLAT_INVZ', 'L2D=T not tested' )
 #ifndef MNH_OPENACC
   CALL GET_HALO( PF_1_Y, HNAME='PF_1_Y' )
 #else
-  CALL GET_HALO_D( PF_1_Y, HNAME='UPDATE_HALO_ll::GET_HALO::PF_1_Y' )
+  CALL GET_HALO_DDC( PF_1_Y, HNAME='PF_1_Y' )
 #endif
   !
   !JUAN Z_SPLITTING