Fix return value of Client.prototype.query in immediate error cases

Author: charmander

lib/client.js

@@ -428,14 +428,14 @@ Client.prototype.query = function (config, values, callback) {
     process.nextTick(() => {
       query.handleError(new Error('Client has encountered a connection error and is not queryable'), this.connection)
     })
-    return
+    return result
   }
 
   if (this._ending) {
     process.nextTick(() => {
       query.handleError(new Error('Client was closed and is not queryable'), this.connection)
     })
-    return
+    return result
   }
 
   this.queryQueue.push(query)