Fix internal build error (#9195)

Summary:
Internal build reported:
```
rocksdb/listener.h:470:3: error: extra ';' inside a struct [-Werror,-Wextra-semi]
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9195

Test Plan: import to fbcode and compile.

Reviewed By: akankshamahajan15

Differential Revision: D32590138

Pulled By: riversand963

fbshipit-source-id: ca4ed9cca210a1a9a12d3de17c789ef9151c57e8

include/rocksdb/listener.h

@@ -467,7 +467,6 @@ struct IOErrorInfo {
   std::string file_path;
   size_t length;
   uint64_t offset;
-  ;
 };
 
 // EventListener class contains a set of callback functions that will