Don't derefence Matrix->SMPkluMatrix->KLUmatrixCommon if it is NULL.

Test for NULL moved upwards in front of dereferencing.

src/maths/KLU/klusmp.c

@@ -535,6 +535,10 @@ SMPcLUfac (SMPmatrix *Matrix, double PivTol)
 
         if (ret == 0)
         {
+            if (Matrix->SMPkluMatrix->KLUmatrixCommon == NULL) {
+                fprintf(stderr, "Error (ReFactor Complex): KLUcommon object is NULL. A problem occurred\n");
+                return 0 ;
+            }
             if (Matrix->SMPkluMatrix->KLUmatrixCommon->status == KLU_SINGULAR) {
                 if (ft_ngdebug) {
                     fprintf(stderr, "Warning (ReFactor Complex): KLU Matrix is SINGULAR\n");
@@ -543,9 +547,6 @@ SMPcLUfac (SMPmatrix *Matrix, double PivTol)
                 }
                 return E_SINGULAR ;
             }
-            if (Matrix->SMPkluMatrix->KLUmatrixCommon == NULL) {
-                fprintf (stderr, "Error (ReFactor Complex): KLUcommon object is NULL. A problem occurred\n") ;
-            }
             if (Matrix->SMPkluMatrix->KLUmatrixCommon->status == KLU_EMPTY_MATRIX)
             {
                 fprintf (stderr, "Error (ReFactor Complex): KLU Matrix is empty\n") ;