Fix frame context pthread_cond leak introduced by 753eef83
diff --git a/src/lib.c b/src/lib.c
index 2348f3a..138301f 100644
--- a/src/lib.c
+++ b/src/lib.c
@@ -594,6 +594,8 @@
             freep(&f->frame_thread.tile_start_off);
             dav1d_freep_aligned(&f->frame_thread.pal);
             freep(&f->frame_thread.cbi);
+        }
+        if (c->n_tc > 1) {
             pthread_cond_destroy(&f->task_thread.cond);
         }
         freep(&f->frame_thread.frame_progress);