Correct the condition for variable statement emit in the declaraiton file

tests/cases/compiler/declareFileExportAssignmentWithVarFromVariableStatement.ts

@@ -0,0 +1,20 @@
+//@module: commonjs
+// @declaration: true
+module m2 {
+    export interface connectModule {
+        (res, req, next): void;
+    }
+    export interface connectExport {
+        use: (mod: connectModule) => connectExport;
+        listen: (port: number) => void;
+    }
+
+}
+
+var x = 10, m2: {
+    (): m2.connectExport;
+    test1: m2.connectModule;
+    test2(): m2.connectModule;
+};
+
+export = m2;