Get rid of no-op calls to QtcProcess::kill()

Leave the work for implicit ProcessReaper.

Change-Id: Ie01c4e996fda18b7cee77851394174556c6f3857
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/projectexplorer/extracompiler.cpp

@@ -426,11 +426,8 @@ void ProcessExtraCompiler::runInThread(
         if (process.waitForFinished(200))
             break;
 
-    if (futureInterface.isCanceled()) {
-        process.kill();
-        process.waitForFinished();
+    if (futureInterface.isCanceled())
         return;
-    }
 
     futureInterface.reportResult(handleProcessFinished(&process));
 }