Fix random encoder lockups (#2707)

* gbk

* surrrely not

* finalize

* such nuance, such nuisance

* this is done automatically

* add back

* give back 0

* simplify

Co-authored-by: Comma Device <device@comma.ai>
old-commit-hash: d25cc6f6241140648b3737afbda51dae310a3bfc

selfdrive/loggerd/encoder.h

@@ -53,6 +53,8 @@ typedef struct EncoderState {
   int num_out_bufs;
   OMX_BUFFERHEADERTYPE** out_buf_headers;
 
+  uint64_t last_t;
+
   Queue free_in;
   Queue done_out;