without a message, it's as if the validate button didn't do anything

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@22330 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/security/PAMSecurityRealm.java

@@ -142,7 +142,7 @@ public class PAMSecurityRealm extends SecurityRealm {
                 else            group=String.valueOf(st.gid());
                 return FormValidation.error(user+" needs to belong to group "+group+" to read /etc/shadow");
             }
-            return FormValidation.ok();
+            return FormValidation.ok("Success");
         }
     }