ffplay: remove redundant prototype

Signed-off-by: Lukasz Marek <lukasz.m.luki@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

ffplay.c

@@ -359,8 +359,6 @@ int64_t get_valid_channel_layout(int64_t channel_layout, int channels)
         return 0;
 }
 
-static int packet_queue_put(PacketQueue *q, AVPacket *pkt);
-
 static int packet_queue_put_private(PacketQueue *q, AVPacket *pkt)
 {
     MyAVPacketList *pkt1;