Apply suggestions from code review

Co-authored-by: Pedro Gomes <38071223+pcarruscag@users.noreply.github.com>

Author: TobiKattmann

SU2_CFD/src/solvers/CScalarSolver.cpp

@@ -711,10 +711,7 @@ void CScalarSolver::LoadRestart(CGeometry** geometry, CSolver*** solver, CConfig
 
     /*--- Skip flow variables ---*/
 
-    unsigned short skipVars = 0;
-
-    if (nDim == 2) skipVars += 6;
-    if (nDim == 3) skipVars += 8;
+    unsigned short skipVars = nDim + solver[MESH_0][FLOW_SOL]->GetnVar();
 
     /*--- Adjust the number of solution variables in the incompressible
      restart. We always carry a space in nVar for the energy equation in the

SU2_CFD/src/solvers/CTurbSASolver.cpp

@@ -1595,10 +1595,7 @@ void CTurbSASolver::ComputeUnderRelaxationFactor(const CConfig *config) {
    SA_NEG model is more robust due to allowing for negative nu_tilde,
    so the under-relaxation is not applied to that variant. */
 
-  bool sa_model = ((config->GetKind_Turb_Model() == SA)        ||
-                   (config->GetKind_Turb_Model() == SA_E)      ||
-                   (config->GetKind_Turb_Model() == SA_COMP)   ||
-                   (config->GetKind_Turb_Model() == SA_E_COMP));
+  if (config->GetKind_Turb_Model() == SA_NEG) return;
 
   /* Loop over the solution update given by relaxing the linear
    system for this nonlinear iteration. */
@@ -1610,19 +1607,11 @@ void CTurbSASolver::ComputeUnderRelaxationFactor(const CConfig *config) {
   for (unsigned long iPoint = 0; iPoint < nPointDomain; iPoint++) {
 
     localUnderRelaxation = 1.0;
-    if (sa_model) {
-      for (unsigned short iVar = 0; iVar < nVar; iVar++) {
-
-        /* We impose a limit on the maximum percentage that the
-          turbulence variables can change over a nonlinear iteration. */
-
-        const unsigned long index = iPoint * nVar + iVar;
-        su2double ratio = fabs(LinSysSol[index]) / (fabs(nodes->GetSolution(iPoint, iVar)) + EPS);
-        if (ratio > allowableRatio) {
-          localUnderRelaxation = min(allowableRatio / ratio, localUnderRelaxation);
-        }
-
-      }
+    su2double ratio = fabs(LinSysSol[iPoint]) / (fabs(nodes->GetSolution(iPoint, 0)) + EPS);
+    /* We impose a limit on the maximum percentage that the
+      turbulence variables can change over a nonlinear iteration. */
+    if (ratio > allowableRatio) {
+      localUnderRelaxation = min(allowableRatio / ratio, localUnderRelaxation);
     }
 
     /* Threshold the relaxation factor in the event that there is