cmd/vet: remove extraneous "//" in dead.go so its comment does not
cmd/vet: remove extraneous "//" in dead.go so its comment does not

appear at the top of vet's godoc output

Change-Id: I2593d294b0497aeb9e8c54a4dad052b5c33ecaee
Reviewed-on: https://go-review.googlesource.com/65630
Reviewed-by: Rob Pike <4dc7c9ec434ed06502767136789763ec11d2c4b7@golang.org>

CAFxX/go,polyverse-security/go,codestation/go,akutz/go,polyverse-security/go,akutz/go,codestation/go,nawawi/go,nawawi/go,Cofyc/go,codestation/go,nawawi/go,CAFxX/go,Cofyc/go,golang/go,polyverse-security/go,polyverse-security/go,codestation/go,nawawi/go,CAFxX/go,akutz/go,josharian/go,josharian/go,cloudflare/go,nawawi/go,Cofyc/go,codestation/go,akutz/go,golang/go,josharian/go,codestation/go,akutz/go,josharian/go,CAFxX/go,polyverse-security/go,cloudflare/go,nawawi/go,golang/go,cloudflare/go,akutz/go,CAFxX/go,cloudflare/go,Cofyc/go,cloudflare/go,Cofyc/go,akutz/go,nawawi/go,golang/go,akutz/go,codestation/go,josharian/go,codestation/go,Cofyc/go,christopher-henderson/Go,Cofyc/go,polyverse-security/go,Cofyc/go,cloudflare/go,golang/go,polyverse-security/go,golang/go,golang/go,CAFxX/go,CAFxX/go,josharian/go,josharian/go,CAFxX/go,golang/go,cloudflare/go,polyverse-security/go,nawawi/go,cloudflare/go,josharian/go