lavfi/framequeue: remove redundant logic code

In this logical branch, fq->queued and fq->allocated must be equal.
Deleting this code will make it easier to understand the logic
(copy the data before tail to the newly requested space)

Signed-off-by: yangyalei <yangyalei@xiaomi.com>

libavfilter/framequeue.c

@@ -79,9 +79,8 @@ int ff_framequeue_add(FFFrameQueue *fq, AVFrame *frame)
             FFFrameBucket *nq = av_realloc_array(fq->queue, na, sizeof(*nq));
             if (!nq)
                 return AVERROR(ENOMEM);
-            if (fq->tail + fq->queued > fq->allocated)
-                memmove(nq + fq->allocated, nq,
-                        (fq->tail + fq->queued - fq->allocated) * sizeof(*nq));
+            if (fq->tail)
+                memmove(nq + fq->allocated, nq, fq->tail * sizeof(*nq));
             fq->queue = nq;
             fq->allocated = na;
         }