[doc/ffi] Fix CString implementation in dart:ffi sample

Change-Id: I3dcb9fefe3d13f21da1c923dd69cc2a994ccf51e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/103128
Auto-Submit: Daco Harkes <dacoharkes@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
Commit-Queue: Daco Harkes <dacoharkes@google.com>

https://dart.googlesource.com/sdk/+/e7f79849953d8f85243cda71d8337f2054241c0a
1 file changed
tree: 40448556f5a50dd9c5a025337d42b49b2a322738
  1. commits.json