TCI - Improve NPE handling

Change-Id: I19f72c4edcec5ffa2264f0acc865a1cb66b84d0f
Signed-off-by: Eugen Neufeld <eneufeld@eclipsesource.com>
diff --git a/bundles/org.eclipse.emfforms.editor/src/org/eclipse/emfforms/spi/editor/GenericEditor.java b/bundles/org.eclipse.emfforms.editor/src/org/eclipse/emfforms/spi/editor/GenericEditor.java
index 380b207..cb41c94 100644
--- a/bundles/org.eclipse.emfforms.editor/src/org/eclipse/emfforms/spi/editor/GenericEditor.java
+++ b/bundles/org.eclipse.emfforms.editor/src/org/eclipse/emfforms/spi/editor/GenericEditor.java
@@ -354,9 +354,10 @@
 		if (getDiagnosticCache() == null || reloading) {
 			return;
 		}
-		if (markerJob != null && markerJob.get() != null) {
-			markerJob.get().cancel();
-			markerJob.compareAndSet(markerJob.get(), null);
+		final Job oldJob = markerJob.get();
+		if (oldJob != null) {
+			oldJob.cancel();
+			markerJob.compareAndSet(oldJob, null);
 		}
 
 		final Job job = Job.create(Messages.GenericEditor_ValidationMarkersJobName, monitor -> {