* small syntax error in parallelheat

demo/src/parallelheat.cc

@@ -55,7 +55,7 @@ public:
     double r2 = (x*x);
     double ux = sin(M_PI * (*timePtr)) * exp(-10.0*r2);
     double ut = M_PI * cos(M_PI*(*timePtr)) * exp(-10.0*r2);
-    return = ut -(400.0*r2 - 20.0*dim)*ux;
+    return ut -(400.0*r2 - 20.0*dim)*ux;
   }
 };