Debraheem/fix eps nuc neu total (#496)

Restore eps_nuc_neu to zones undergoing operator split burn. This fixes the history output for 'eps_nuc_neu_total', 'log_Lneu', and 'log_Lneu_nuc'.

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Co-authored-by: EbF <[email protected]>

Author: rjfarmer

star/private/struct_burn_mix.f90

@@ -1197,7 +1197,8 @@ subroutine burn1_zone( &
          s% d_dxdt_nuc_dRho(:,k) =  0d0
          s% d_dxdt_nuc_dT(:,k) =  0d0
          s% d_dxdt_nuc_dx(:,:,k) =  0d0
-         s% eps_nuc_neu_total(k) = 0d0
+         ! below, restore eps_nuc_neu to op_split zones.
+         s% eps_nuc_neu_total(k) = ending_eps_neu_total 
 
          do i=1,species ! for use by dX_nuc_drop timestep limiter
             s% dxdt_nuc(i,k) = (s% xa(i,k)-xa_start(i))/dt