Update log_reader.h

db/log_reader.h

@@ -24,7 +24,7 @@ class Reader {
    public:
     virtual ~Reporter();
 
-    // Some corruption was detected.  "size" is the approximate number
+    // Some corruption was detected.  "bytes" is the approximate number
     // of bytes dropped due to the corruption.
     virtual void Corruption(size_t bytes, const Status& status) = 0;
   };