Enabled start/stop when testing counters

A bit more thorough, you test they start/stop correctly.

core/src/main/kotlin/se/lth/cs/papicounters/PAPICounter.kt

@@ -6,7 +6,6 @@ import papi.PapiException
 import se.lth.cs.CounterSpecification
 import se.lth.cs.util.Feature
 import se.lth.cs.util.FeatureVisitor
-import java.lang.RuntimeException
 
 class PAPICounter(val counter : String) : Feature() {
     fun isValid(): Boolean {
@@ -17,14 +16,14 @@ class PAPICounter(val counter : String) : Feature() {
         Papi.init()
         try {
             val eventSet = EventSet.create(this.toPAPIConstant()!!)
-            // eventSet.start()
-            // var x = 0
-            // // Some random crap
-            // for (i in 0 until 10) {
-            //     x += x * 2 - 3
-            // }
-            // eventSet.stop()
-            // eventSet.destroy()
+            eventSet.start()
+            var x = 0
+            // Some random crap
+            for (i in 0 until 10) {
+                x += x * 2 - 3
+            }
+            eventSet.stop()
+            eventSet.destroy()
             return true
         } catch (e : PapiException) {
             return false