Made test more clear

Author: patrick-sko

test/com/google/javascript/jscomp/AstValidatorTest.java

@@ -1275,8 +1275,6 @@ public void testSwitchStatement() {
         "  switch(x) {",
         "    case 1: ",
         "      var y = 5;",
-        "    default:",
-        "      var y = 5;",
         "    case 2: ",
         "      var y = 5;",
         "  }",
@@ -1285,15 +1283,15 @@ public void testSwitchStatement() {
     valid(switchStatement);
 
     Node rootScriptNode = parseValidScript(switchStatement);
-    Node defaultBlock = IR.block();
+    Node blockNode = IR.block();
 
     Node nodeToAppendChildTo =
         stream(NodeUtil.preOrderIterable(rootScriptNode))
             .filter(node -> node.isCase())
             .findFirst()
             .get();
 
-    nodeToAppendChildTo.addChildToFront(defaultBlock);
+    nodeToAppendChildTo.addChildToFront(blockNode);
     expectInvalid(rootScriptNode, Check.SCRIPT);
   }