Resolve review comments: No functional change

fdbserver/DDTeamCollection.actor.cpp

@@ -4242,7 +4242,7 @@ int DDTeamCollection::addBestMachineTeams(int machineTeamsToBuild) {
 		} else {
 			// When too many teams exist in simulation, traceAllInfo will buffer too many trace logs before
 			// trace has a chance to flush its buffer, which causes assertion failure.
-			traceAllInfo(g_network->isSimulated() ? false : true);
+			traceAllInfo(!g_network->isSimulated());
 			TraceEvent(SevWarn, "DataDistributionBuildTeams", distributorId)
 			    .detail("Primary", primary)
 			    .detail("Reason", "Unable to make desired machine Teams")

flow/flow.cpp

@@ -449,6 +449,7 @@ void bindDeterministicRandomToOpenssl() {
 }
 
 int nChooseK(int n, int k) {
+	assert(n >= k && k >= 0);
 	if (k == 0) {
 		return 1;
 	}

flow/include/flow/flow.h

@@ -100,6 +100,7 @@ extern StringRef strinc(StringRef const& str, Arena& arena);
 extern Standalone<StringRef> addVersionStampAtEnd(StringRef const& str);
 extern StringRef addVersionStampAtEnd(StringRef const& str, Arena& arena);
 
+// Return the number of combinations to choose k items out of n choices
 int nChooseK(int n, int k);
 
 template <typename Iter>