small cleanup in ReadVariableNode

com.oracle.truffle.r.nodes/src/com/oracle/truffle/r/nodes/access/variables/ReadVariableNode.java

@@ -104,8 +104,7 @@ public final class ReadVariableNode extends RSourceSectionNode implements RSynta
     }
 
     public static ReadVariableNode create(SourceSection src, String name, boolean shouldCopyValue) {
-        ReadVariableNode rvn = new ReadVariableNode(src, name, RType.Any, shouldCopyValue ? ReadKind.Copying : ReadKind.Normal);
-        return rvn;
+        return new ReadVariableNode(src, name, RType.Any, shouldCopyValue ? ReadKind.Copying : ReadKind.Normal);
     }
 
     public static ReadVariableNode createSilent(String name, RType mode) {
@@ -113,18 +112,15 @@ public final class ReadVariableNode extends RSourceSectionNode implements RSynta
     }
 
     public static ReadVariableNode createSuperLookup(SourceSection src, String name) {
-        ReadVariableNode rvn = new ReadVariableNode(src, name, RType.Any, ReadKind.Super);
-        return rvn;
+        return new ReadVariableNode(src, name, RType.Any, ReadKind.Super);
     }
 
     public static ReadVariableNode createFunctionLookup(SourceSection src, String identifier) {
-        ReadVariableNode result = new ReadVariableNode(src, identifier, RType.Function, ReadKind.Normal);
-        return result;
+        return new ReadVariableNode(src, identifier, RType.Function, ReadKind.Normal);
     }
 
     public static ReadVariableNode createForcedFunctionLookup(SourceSection src, String name) {
-        ReadVariableNode result = new ReadVariableNode(src, name, RType.Function, ReadKind.ForcedTypeCheck);
-        return result;
+        return new ReadVariableNode(src, name, RType.Function, ReadKind.ForcedTypeCheck);
     }
 
     @Child private PromiseHelperNode promiseHelper;