qemu-file: Rework old qemu_fflush comment

Commit 11808bb removed the non-iovec based write support,
the comment hung on.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20190823103946.7388-1-dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

migration/qemu-file.c

@@ -201,9 +201,8 @@ static void qemu_iovec_release_ram(QEMUFile *f)
 /**
  * Flushes QEMUFile buffer
  *
- * If there is writev_buffer QEMUFileOps it uses it otherwise uses
- * put_buffer ops. This will flush all pending data. If data was
- * only partially flushed, it will set an error state.
+ * This will flush all pending data. If data was only partially flushed, it
+ * will set an error state.
  */
 void qemu_fflush(QEMUFile *f)
 {