Made stream explicitely sequential

We don't want the stream to be parallel by mistake, that would destroy
the measurements.

core/src/main/kotlin/se/lth/cs/commandline/PapiCommandLine.kt

@@ -109,7 +109,7 @@ class PapiCommandLine : CliktCommand() {
             else -> null
         }
 
-        printer!!.printStreamToCSV(benchmarks!!)
+        printer!!.printStreamToCSV(benchmarks!!.sequential())
 
     }