pthread_frame: revert 2e664b9c.

The patch does not fix the tsan warning it was intended to fix.
Reverting the patch moves the av_log() back to the outside of the lock.

Signed-off-by: Wan-Teh Chang <wtc@google.com>
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

libavcodec/pthread_frame.c

@@ -570,11 +570,12 @@ void ff_thread_report_progress(ThreadFrame *f, int n, int field)
 
     p = f->owner[field]->internal->thread_ctx;
 
-    pthread_mutex_lock(&p->progress_mutex);
     if (atomic_load_explicit(&p->debug_threads, memory_order_relaxed))
         av_log(f->owner[field], AV_LOG_DEBUG,
                "%p finished %d field %d\n", progress, n, field);
 
+    pthread_mutex_lock(&p->progress_mutex);
+
     atomic_store_explicit(&progress[field], n, memory_order_release);
 
     pthread_cond_broadcast(&p->progress_cond);
@@ -592,10 +593,11 @@ void ff_thread_await_progress(ThreadFrame *f, int n, int field)
 
     p = f->owner[field]->internal->thread_ctx;
 
-    pthread_mutex_lock(&p->progress_mutex);
     if (atomic_load_explicit(&p->debug_threads, memory_order_relaxed))
         av_log(f->owner[field], AV_LOG_DEBUG,
                "thread awaiting %d field %d from %p\n", n, field, progress);
+
+    pthread_mutex_lock(&p->progress_mutex);
     while (atomic_load_explicit(&progress[field], memory_order_relaxed) < n)
         pthread_cond_wait(&p->progress_cond, &p->progress_mutex);
     pthread_mutex_unlock(&p->progress_mutex);