avcodec/threadframe: Constify the frame in ff_thread_await_progress

It is safe to call it on a const ThreadFrame*.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavcodec/pthread_frame.c

@@ -615,7 +615,7 @@ void ff_thread_report_progress(ThreadFrame *f, int n, int field)
     pthread_mutex_unlock(&p->progress_mutex);
 }
 
-void ff_thread_await_progress(ThreadFrame *f, int n, int field)
+void ff_thread_await_progress(const ThreadFrame *f, int n, int field)
 {
     PerThreadContext *p;
     atomic_int *progress = f->progress ? (atomic_int*)f->progress->data : NULL;

libavcodec/threadframe.h

@@ -56,7 +56,7 @@ void ff_thread_report_progress(ThreadFrame *f, int progress, int field);
  * @param field The field being referenced, for field-picture codecs.
  * 0 for top field or frame pictures, 1 for bottom field.
  */
-void ff_thread_await_progress(ThreadFrame *f, int progress, int field);
+void ff_thread_await_progress(const ThreadFrame *f, int progress, int field);
 
 /**
  * Wrapper around ff_get_buffer() for frame-multithreaded codecs.

libavcodec/utils.c

@@ -949,7 +949,7 @@ void ff_thread_report_progress(ThreadFrame *f, int progress, int field)
 {
 }
 
-void ff_thread_await_progress(ThreadFrame *f, int progress, int field)
+void ff_thread_await_progress(const ThreadFrame *f, int progress, int field)
 {
 }