some clang-tidy in test_sdc (#1784)

Author: zingale

unit_test/test_sdc/main.cpp

@@ -252,7 +252,8 @@ void main_main ()
 
     // print statistics
     std::cout << "min number of rhs calls: " << n_rhs_min << std::endl;
-    std::cout << "avg number of rhs calls: " << n_rhs_sum / (n_cell*n_cell*n_cell) << std::endl;
+    std::cout << "avg number of rhs calls: "
+              << static_cast<Real>(n_rhs_sum) / static_cast<Real>(n_cell*n_cell*n_cell) << std::endl;
     std::cout << "max number of rhs calls: " << n_rhs_max << std::endl;
 
 }

unit_test/test_sdc/react_zones.H

@@ -76,8 +76,8 @@ bool do_react (const plot_t& p, const int i, const int j, const int k,
 
     // zero out the advective terms
 
-    for (int n = 0; n < SVAR; n++) {
-        burn_state.ydot_a[n] = 0.0;
+    for (auto& e : burn_state.ydot_a) {
+        e = 0.0;
     }