Ruby: fix a couple of references to deprecated names

Author: nickrolfe

ruby/ql/lib/codeql/ruby/security/XSS.qll

@@ -62,7 +62,7 @@ private module Shared {
    */
   class HtmlSafeCallAsSink extends Sink {
     HtmlSafeCallAsSink() {
-      exists(HtmlSafeCall c, ErbOutputDirective d |
+      exists(Rails::HtmlSafeCall c, ErbOutputDirective d |
         this.asExpr().getExpr() = c.getReceiver() and
         c = d.getTerminalStmt()
       )
@@ -160,7 +160,7 @@ private module Shared {
    */
   pragma[noinline]
   private predicate renderCallLocals(string hashKey, Expr value, ErbFile erb) {
-    exists(RenderCall call, Pair kvPair |
+    exists(Rails::RenderCall call, Pair kvPair |
       call.getLocals().getAKeyValuePair() = kvPair and
       kvPair.getValue() = value and
       kvPair.getKey().getConstantValue().isStringlikeValue(hashKey) and