STYLE: convert to new time loop structure

applications/solvers/compressible/rhoSimplecFoam/rhoSimplecFoam.C

@@ -50,7 +50,7 @@ int main(int argc, char *argv[])
 
     Info<< "\nStarting time loop\n" << endl;
 
-    for (runTime++; !runTime.end(); runTime++)
+    while (runTime.loop())
     {
         Info<< "Time = " << runTime.timeName() << nl << endl;