Fix lint

Author: sandersn

src/compiler/declarationEmitter.ts

@@ -67,7 +67,7 @@ namespace ts {
         let errorNameNode: DeclarationName;
         const emitJsDocComments = compilerOptions.removeComments ? noop : writeJsDocComments;
         const emit = compilerOptions.stripInternal ? stripInternal : emitNode;
-        let needsDeclare: boolean = true;
+        let needsDeclare = true;
 
         let moduleElementDeclarationEmitInfo: ModuleElementDeclarationEmitInfo[] = [];
         let asynchronousSubModuleDeclarationEmitInfo: ModuleElementDeclarationEmitInfo[];