Fix double-callback-call crash in //remoting/host/file_transfer/

Fix bug found by the "bugprone-use-after-move" clang-tidy check.

Bug: 1122844
Change-Id: I0b3d37aeebc855e62b5f42af5d886b53fab1dc6c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2386728
Commit-Queue: Joe Downing <joedow@chromium.org>
Reviewed-by: Joe Downing <joedow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#803547}

remoting/host/file_transfer/local_file_operations.cc

@@ -430,6 +430,7 @@ void LocalFileWriter::OnCreateResult(Callback callback,
     SetState(FileOperations::kFailed);
     std::move(callback).Run(protocol::MakeFileTransferError(
         FROM_HERE, FileErrorToResponseErrorType(error), error));
+    return;
   }
 
   SetState(FileOperations::kReady);