Make createAttributeNS's qualifiedName argument non-nullable

LayoutTests/fast/dom/Document/script-tests/createAttributeNS-namespace-err.js

Index: LayoutTests/fast/dom/Document/script-tests/createAttributeNS-namespace-err.js
diff --git a/LayoutTests/fast/dom/Document/script-tests/createAttributeNS-namespace-err.js b/LayoutTests/fast/dom/Document/script-tests/createAttributeNS-namespace-err.js
index 06cfde23ebff67e0a1e47ac635ff4e4d0859a454..7f25d8abda2b7f19089ec109d30ba9e93800cace 100644
--- a/LayoutTests/fast/dom/Document/script-tests/createAttributeNS-namespace-err.js
+++ b/LayoutTests/fast/dom/Document/script-tests/createAttributeNS-namespace-err.js
@@ -38,10 +38,10 @@ function assertExceptionCode(exception, expect, m)
 var allNSTests = [
    { args: [undefined, undefined] },
    { args: [null, undefined] },
-   { args: [undefined, null], code: 5 },
-   { args: [null, null], code: 5 },
+   { args: [undefined, null] },
+   { args: [null, null] },
    { args: [null, ""], code: 5 },
-   { args: ["", null], code: 5 },
+   { args: ["", null] },
    { args: ["", ""], code: 5 },
    { args: [null, "<div>"], code: 5 },
    { args: [null, "0div"], code: 5 },