make sure ALL_Staggered_f is Fortran 2003 compatible

example/ALL_Staggered_f.F90

@@ -33,14 +33,14 @@ program ALL_Staggered_f
     use, intrinsic :: iso_fortran_env, only: stdin=>input_unit&
         , stdout=>output_unit&
         , stderr=>error_unit&
-        , file_storage_size&
-        ,int32,int64,real32,real64
+        , file_storage_size
 #ifndef ALL_USE_F08
     use mpi
 #else
     use mpi_f08
 #endif
     implicit none
+    integer, parameter :: real64 = selected_real_kind(15)
 
     call main()
 contains
@@ -132,6 +132,9 @@ contains
         integer :: my_rank, maximum_rank
         integer :: i,j
         type(ALL_t) :: jall
+#ifdef ALL_VTK_OUTPUT
+        character (len=ALL_ERROR_LENGTH) :: error_msg
+#endif
 
         call MPI_Init(error)
 
@@ -200,8 +203,6 @@ contains
                 flush(stdout)
             endif
 #ifdef ALL_VTK_OUTPUT
-            block
-                character (len=ALL_ERROR_LENGTH) :: error_msg
             call ALL_reset_error()
             call jall%print_vtk_outlines(current_step)
             if(ALL_error() /= 0) then
@@ -210,7 +211,6 @@ contains
                 ! Maybe also abort if the output is necesssary or handle this
                 ! some other way.
             endif
-            end block
 #endif
             call jall%balance()
 
@@ -221,8 +221,6 @@ contains
             call MPI_Barrier(MPI_COMM_WORLD, error)
         enddo
 #ifdef ALL_VTK_OUTPUT
-        block
-            character (len=ALL_ERROR_LENGTH) :: error_msg
         call ALL_reset_error()
         call jall%print_vtk_outlines(current_step)
         if(ALL_error() /= 0) then
@@ -231,7 +229,6 @@ contains
             ! Maybe also abort if the output is necesssary or handle this
             ! some other way.
         endif
-        end block
 #endif
 
         call jall%finalize()