Get rid of initialization of flux_derivatives_generalized

WENO.F90

@@ -51,20 +51,6 @@ subroutine compute_flux_derivatives(nvars, ndim, nx, ny, nz, &
   delta_eta = 1.0
   delta_zeta = 1.0
 
-  !$loopy begin tagged: init_flux
-  do k=1,nz
-    do j=1,ny
-      do i=1,nx
-        do l=1,ndim
-          do m=1,nvars
-            flux_derivatives_generalized(m, l, i, j, k) = 0.0
-          end do
-        end do
-      end do
-    end do
-  end do
-  !$loopy end tagged: init_flux
-
   !$loopy begin tagged: to_generalized
   call convert_to_generalized(nvars, ndim, nx, ny, nz, &
     fluxes, metrics, metric_jacobians, generalized_fluxes)
@@ -115,8 +101,7 @@ subroutine compute_flux_derivatives(nvars, ndim, nx, ny, nz, &
       do i=1,nx
         do v=1,nvars
           flux_derivatives_generalized(v, 1, i, j, k) = &
-            flux_derivatives_generalized(v, 1, i, j, k) &
-            + (weno_flux_tmp(v, i, j, k) - weno_flux_tmp(v, i-1, j, k)) / delta_xi
+            (weno_flux_tmp(v, i, j, k) - weno_flux_tmp(v, i-1, j, k)) / delta_xi
         end do
       end do
     end do