remove stray tab, fix comment

modules/lang-painless/src/main/antlr/PainlessParser.g4

@@ -204,7 +204,7 @@ funcref
 // reference to a static or instance method, e.g. ArrayList::size or Integer::compare
 classFuncref
     : TYPE REF ID
-	;
+    ;
 
 // reference to a constructor, e.g. ArrayList::new
 // currently limited to simple non-array types

modules/lang-painless/src/main/java/org/elasticsearch/painless/node/EChain.java

@@ -48,7 +48,7 @@ public final class EChain extends AExpression {
     Cast there = null;
     Cast back = null;
     
-    /** Creates a new simple EChain */
+    /** Creates a new RHS-only EChain */
     public EChain(Location location, ALink link) {
         this(location, Arrays.asList(link), false, false, null, null);
     }