fix: wrong var

Author: hacdias

src/stats/bw.js

@@ -10,10 +10,10 @@ const transform = function (res, callback) {
     }
 
     callback(null, {
-      totalIn: res[0].TotalIn,
-      totalOut: res[0].TotalOut,
-      rateIn: res[0].RateIn,
-      rateOut: res[0].RateOut
+      totalIn: data[0].TotalIn,
+      totalOut: data[0].TotalOut,
+      rateIn: data[0].RateIn,
+      rateOut: data[0].RateOut
     })
   })
 }