Fix all linting errors

Disabled gocylco for now, need to use gometalinter to disable
conditionally. There are also a lot more linters we could use, but they
cause too many issues to start today.

internal/sctp/param_forward_tsn_supported.go

@@ -2,7 +2,6 @@ package sctp
 
 type paramForwardTSNSupported struct {
 	paramHeader
-	chunkTypes []chunkType
 }
 
 func (f *paramForwardTSNSupported) marshal() ([]byte, error) {