Fixed atomic var -> val

Author: elizarov

core/kotlinx-coroutines-core/test/internal/LockFreeMPSCQueueStressTest.kt

@@ -21,7 +21,7 @@ class LockFreeMPSCQueueStressTest : TestBase() {
     private val consumed = atomic(0L)
     private var expected = LongArray(nProducers)
 
-    private var queue = atomic<LockFreeMPSCQueue<Item>?>(null)
+    private val queue = atomic<LockFreeMPSCQueue<Item>?>(null)
     private val done = atomic(0)
     private val doneProducers = atomic(0)
 

core/kotlinx-coroutines-core/test/scheduling/SchedulerTestBase.kt

@@ -59,7 +59,7 @@ abstract class SchedulerTestBase : TestBase() {
         suspend fun Iterable<Job>.joinAll() = forEach { it.join() }
     }
 
-    private var exception = atomic<Throwable?>(null)
+    private val exception = atomic<Throwable?>(null)
     private val handler = CoroutineExceptionHandler({ _, e -> exception.value = e })
 
     protected var corePoolSize = 1