libfdk-aacenc: Fix assignments in if()

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/libfdk-aacenc.c

@@ -334,7 +334,7 @@ static int aac_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
         in_buf.bufElSizes        = &in_buffer_element_size;
 
         /* add current frame to the queue */
-        if ((ret = ff_af_queue_add(&s->afq, frame) < 0))
+        if ((ret = ff_af_queue_add(&s->afq, frame)) < 0)
             return ret;
     }