Possible socket leak when Bind fails

[vulcanfan]

Hi,

Just raising possible bug in line 215 of sctp_linux.go which says

err := SCTPBind(sock, laddr, SCTP_BINDX_ADD_ADDR)

whereby if the socket fails to bind for whatever reason the defer() to close the socket isn't called, and the socket leaks. Cause appears to be the := instead = above. Declaring a new err variable with := masks the err that is checked in the defer(). Suggest changing := to just = may resolve.

Thanks