Remove extra checks that are not needed

src/vs/workbench/browser/editor.ts

@@ -140,7 +140,7 @@ class EditorRegistry implements IEditorRegistry {
 		};
 
 		const descriptors = findEditorDescriptors(input);
-		if (descriptors && descriptors.length > 0) {
+		if (descriptors.length > 0) {
 
 			// Ask the input for its preferred Editor
 			const preferredEditorId = input.getPreferredEditorId(descriptors.map(d => d.getId()));

src/vs/workbench/common/editor.ts

@@ -381,7 +381,7 @@ export abstract class EditorInput extends Disposable implements IEditorInput {
 	 * for the input. This allows subclasses to decide late which editor to use for the input on a case by case basis.
 	 */
 	getPreferredEditorId(candidates: string[]): string | null {
-		if (candidates && candidates.length > 0) {
+		if (candidates.length > 0) {
 			return candidates[0];
 		}