Fix formatting errors

Fixed the formatting errors introduced by Astyle. Changed the comment
syntax to use a more Astyle-friendly one.

server/core/dcb.cc

@@ -1157,8 +1157,8 @@ void dcb_final_close(DCB* dcb)
 
     if (dcb->dcb_role == DCB_ROLE_BACKEND_HANDLER &&  // Backend DCB
         dcb->state == DCB_STATE_POLLING &&            // Being polled
-        dcb->persistentstart == 0 &&                  // Not already in (> 0) or being evicted from (-1)
-        // the persistent pool.
+        dcb->persistentstart == 0 &&                  /** Not already in (> 0) or being evicted from (-1)
+                                                       * the persistent pool. */
         dcb->server)                                  // And has a server
     {
         /* May be a candidate for persistence, so save user name */