Fix typo in env_win.h (facebook#9138)

Summary:
overide -> override

Pull Request resolved: facebook#9138

Reviewed By: jay-zhuang

Differential Revision: D32245235

Pulled By: mrambacher

fbshipit-source-id: bed62b843925bed806c06ca3485d33bb45a56dc7

port/win/env_win.h

@@ -201,7 +201,7 @@ class WinFileSystem : public FileSystem {
                             IODebugContext* dbg) override;
 
   // Create and returns a default logger (an instance of EnvLogger) for storing
-  // informational messages. Derived classes can overide to provide custom
+  // informational messages. Derived classes can override to provide custom
   // logger.
   IOStatus NewLogger(const std::string& fname, const IOOptions& io_opts,
                      std::shared_ptr<Logger>* result,