sctp: remove the unused typedef sctp_packet_phandler_t

Remove this function typedef, there is even no places
using it.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/net/sctp/structs.h

@@ -657,8 +657,6 @@ struct sctp_sockaddr_entry {
 
 #define SCTP_ADDRESS_TICK_DELAY	500
 
-typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *);
-
 /* This structure holds lists of chunks as we are assembling for
  * transmission.
  */