src: remove reference to since-deleted dist -s flag
src: remove reference to since-deleted dist -s flag

(Found while debugging release problems with go1.6beta1)

Updates #12002

Change-Id: Iec197a754205e7fd28be154f27f17f3315886364
Reviewed-on: https://go-review.googlesource.com/18011
Reviewed-by: Chris Broadfoot <0c2851a4f8ab4aa5606e69c0757771dd13dbe686@golang.org>

ganboing/go-esx,ImJasonH/go,nawawi/go,vanloswang/go,mwhudson/go,Endika/go,linux-on-ibm-z/go,suncycheng/go,polyverse-security/go,polyverse-security/go,linux-on-ibm-z/go,vanloswang/go,momchil-velikov/go,vanloswang/go,roth1002/go,cloudflare/go,roth1002/go,4ad/go,nawawi/go,polyverse-security/go,Cofyc/go,cyberroadie/go,polyverse-security/go,vanloswang/go,ImJasonH/go,theif519/go,vsekhar/elastic-go,sndnvaps/go,akutz/go,mwhudson/go,miolini/go,linux-on-ibm-z/go,cyberroadie/go,polyverse-security/go,CAFxX/go,kim-racktop/go,vsekhar/elastic-go,Cofyc/go,nawawi/go,codestation/go,Cofyc/go,goodlang/good,Cofyc/go,momchil-velikov/go,momchil-velikov/go,sndnvaps/go,nawawi/go,nawawi/go,miolini/go,derekmarcotte/go,mwhudson/go,CAFxX/go,polyverse-security/go,akutz/go,CAFxX/go,ganboing/go-esx,Endika/go,binarycrusader/go,derekmarcotte/go,ganboing/go-esx,vanloswang/go,kim-racktop/go,ganboing/go-esx,cyberroadie/go,4ad/go,golang/go,Cofyc/go,josharian/go,miolini/go,miolini/go,vanloswang/go,binarycrusader/go,akutz/go,CAFxX/go,goodlang/good,akutz/go,suncycheng/go,miolini/go,golang/go,cyberroadie/go,CAFxX/go,kim-racktop/go,goodlang/good,theif519/go,Endika/go,Cofyc/go,binarycrusader/go,Samurais/go,nawawi/go,CAFxX/go,cloudflare/go,suncycheng/go,CAFxX/go,akutz/go,Samurais/go,sndnvaps/go,binarycrusader/go,binarycrusader/go,akutz/go,mwhudson/go,codestation/go,josharian/go,cyberroadie/go,vsekhar/elastic-go,vanloswang/go,josharian/go,golang/go,codestation/go,4ad/go,roth1002/go,vsekhar/elastic-go,Samurais/go,vsekhar/elastic-go,ganboing/go-esx,4ad/go,ImJasonH/go,momchil-velikov/go,vsekhar/elastic-go,Cofyc/go,suncycheng/go,polyverse-security/go,momchil-velikov/go,binarycrusader/go,Cofyc/go,suncycheng/go,golang/go,4ad/go,sndnvaps/go,derekmarcotte/go,goodlang/good,Samurais/go,linux-on-ibm-z/go,nawawi/go,cloudflare/go,mwhudson/go,miolini/go,goodlang/good,kim-racktop/go,Endika/go,ganboing/go-esx,josharian/go,sndnvaps/go,kim-racktop/go,goodlang/good,linux-on-ibm-z/go,mwhudson/go,cloudflare/go,miolini/go,roth1002/go,CAFxX/go,goodlang/good,cyberroadie/go,sndnvaps/go,Endika/go,theif519/go,christopher-henderson/Go,theif519/go,akutz/go,golang/go,golang/go,codestation/go,derekmarcotte/go,theif519/go,codestation/go,sndnvaps/go,golang/go,cyberroadie/go,cloudflare/go,vsekhar/elastic-go,codestation/go,ImJasonH/go,polyverse-security/go,Samurais/go,theif519/go,momchil-velikov/go,codestation/go,Samurais/go,4ad/go,roth1002/go,sndnvaps/go,Endika/go,Samurais/go,cloudflare/go,derekmarcotte/go,kim-racktop/go,binarycrusader/go,vanloswang/go,ImJasonH/go,codestation/go,nawawi/go,ImJasonH/go,josharian/go,vsekhar/elastic-go,4ad/go,mwhudson/go,suncycheng/go,golang/go,ImJasonH/go,mwhudson/go,theif519/go,derekmarcotte/go,momchil-velikov/go,Endika/go,momchil-velikov/go,josharian/go,suncycheng/go,linux-on-ibm-z/go,derekmarcotte/go,binarycrusader/go,josharian/go,Endika/go,cloudflare/go,suncycheng/go,roth1002/go,linux-on-ibm-z/go,ganboing/go-esx,linux-on-ibm-z/go,ganboing/go-esx,ImJasonH/go,akutz/go,Samurais/go,theif519/go,miolini/go,cloudflare/go,goodlang/good,derekmarcotte/go,cyberroadie/go,josharian/go,kim-racktop/go,4ad/go,roth1002/go,roth1002/go,kim-racktop/go