[Runtime] don't allocate threads array twice

the threads array is initialized using the Runtime::Runtime initializer list
and afterwards again in the constructor.

emper/Runtime.cpp

@@ -52,8 +52,6 @@ Runtime::Runtime(workerid_t workerCount, RuntimeStrategy& strategy, unsigned int
 			randomEngine(seed),
 			atLeastOneWorkerIsSleeping(false),
 			skipSleep(false) {
-	threads = new pthread_t[workerCount];
-
 	const int nprocs = get_nprocs();
 
 	{