archive/tar: make Reader.Read errors persistent
archive/tar: make Reader.Read errors persistent

If the stream is in an inconsistent state, it does not make sense
that Reader.Read can be called and possibly succeed.

Change-Id: I9d1c5a1300b2c2b45232188aa7999e350809dcf2
Reviewed-on: https://go-review.googlesource.com/15177
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>
Run-TryBot: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>

vanloswang/go,Cofyc/go,polyverse-security/go,ganboing/go-esx,ImJasonH/go,miolini/go,kim-racktop/go,Samurais/go,josharian/go,CAFxX/go,theif519/go,rachtsingh/gogojuice,nawawi/go,miolini/go,fjballest/golang,Endika/go,mwhudson/go,cyberroadie/go,malvira/go,vanloswang/go,golang/go,4ad/go,momchil-velikov/go,4ad/go,codestation/go,dterei/go,rachtsingh/gogojuice,derekmarcotte/go,Jordanzuo/go,mwhudson/go,Endika/go,josharian/go,mwhudson/go,4ad/go,vsekhar/elastic-go,miolini/go,vanloswang/go,vanloswang/go,Samurais/go,momchil-velikov/go,deft-code/go,fjballest/golang,miolini/go,roth1002/go,momchil-velikov/go,gdey/go,odeke-em/go,4ad/go,ImJasonH/go,4ad/go,derekmarcotte/go,dterei/go,malvira/go,goodlang/good,binarycrusader/go,ImJasonH/go,rachtsingh/gogojuice,suncycheng/go,rachtsingh/gogojuice,theif519/go,rachtsingh/gogojuice,kim-racktop/go,Endika/go,sndnvaps/go,goodlang/good,polyverse-security/go,jacobsa/go,dterei/go,akutz/go,odeke-em/go,golang/go,Cofyc/go,Cofyc/go,vanloswang/go,jacobsa/go,kim-racktop/go,Cofyc/go,linux-on-ibm-z/go,fjballest/golang,polyverse-security/go,odeke-em/go,binarycrusader/go,Endika/go,4ad/go,suncycheng/go,Endika/go,josharian/go,ganboing/go-esx,goodlang/good,suncycheng/go,theif519/go,gdey/go,Endika/go,jacobsa/go,kim-racktop/go,vanloswang/go,sndnvaps/go,mwhudson/go,linux-on-ibm-z/go,CAFxX/go,roth1002/go,odeke-em/go,jacobsa/go,dterei/go,cloudflare/go,ImJasonH/go,miolini/go,derekmarcotte/go,vsekhar/elastic-go,gdey/go,linux-on-ibm-z/go,mwhudson/go,4ad/go,dterei/go,CAFxX/go,nawawi/go,sndnvaps/go,deft-code/go,sndnvaps/go,polyverse-security/go,vsekhar/elastic-go,deft-code/go,derekmarcotte/go,roth1002/go,derekmarcotte/go,dterei/go,golang/go,derekmarcotte/go,gdey/go,akutz/go,miolini/go,ganboing/go-esx,ganboing/go-esx,deft-code/go,roth1002/go,momchil-velikov/go,CAFxX/go,kim-racktop/go,sndnvaps/go,fjballest/golang,CAFxX/go,cyberroadie/go,golang/go,CAFxX/go,roth1002/go,odeke-em/go,vsekhar/elastic-go,josharian/go,linux-on-ibm-z/go,suncycheng/go,malvira/go,codestation/go,fjballest/golang,josharian/go,gdey/go,nawawi/go,suncycheng/go,jacobsa/go,theif519/go,nawawi/go,ImJasonH/go,golang/go,deft-code/go,cyberroadie/go,Samurais/go,rachtsingh/gogojuice,Samurais/go,odeke-em/go,Cofyc/go,binarycrusader/go,momchil-velikov/go,codestation/go,theif519/go,roth1002/go,deft-code/go,josharian/go,nawawi/go,josharian/go,goodlang/good,linux-on-ibm-z/go,Jordanzuo/go,mwhudson/go,malvira/go,miolini/go,codestation/go,codestation/go,christopher-henderson/Go,mwhudson/go,Endika/go,vsekhar/elastic-go,vsekhar/elastic-go,malvira/go,golang/go,momchil-velikov/go,CAFxX/go,binarycrusader/go,ganboing/go-esx,polyverse-security/go,cloudflare/go,binarycrusader/go,kim-racktop/go,suncycheng/go,nawawi/go,Jordanzuo/go,cyberroadie/go,cyberroadie/go,gdey/go,suncycheng/go,malvira/go,goodlang/good,Jordanzuo/go,vsekhar/elastic-go,codestation/go,cloudflare/go,ImJasonH/go,polyverse-security/go,deft-code/go,malvira/go,goodlang/good,roth1002/go,fjballest/golang,akutz/go,nawawi/go,jacobsa/go,momchil-velikov/go,ganboing/go-esx,Samurais/go,Samurais/go,dterei/go,ganboing/go-esx,golang/go,jacobsa/go,jacobsa/go,akutz/go,theif519/go,derekmarcotte/go,deft-code/go,cloudflare/go,goodlang/good,sndnvaps/go,Samurais/go,golang/go,CAFxX/go,suncycheng/go,dterei/go,vanloswang/go,rachtsingh/gogojuice,kim-racktop/go,binarycrusader/go,sndnvaps/go,Jordanzuo/go,vsekhar/elastic-go,Cofyc/go,fjballest/golang,codestation/go,codestation/go,binarycrusader/go,Cofyc/go,linux-on-ibm-z/go,cyberroadie/go,derekmarcotte/go,miolini/go,vanloswang/go,akutz/go,linux-on-ibm-z/go,roth1002/go,malvira/go,cloudflare/go,akutz/go,goodlang/good,sndnvaps/go,Jordanzuo/go,nawawi/go,polyverse-security/go,rachtsingh/gogojuice,fjballest/golang,kim-racktop/go,cyberroadie/go,cyberroadie/go,Jordanzuo/go,momchil-velikov/go,binarycrusader/go,akutz/go,linux-on-ibm-z/go,akutz/go,gdey/go,mwhudson/go,cloudflare/go,josharian/go,gdey/go,theif519/go,ganboing/go-esx,theif519/go,odeke-em/go,ImJasonH/go,cloudflare/go,Samurais/go,cloudflare/go,Endika/go,Cofyc/go,Jordanzuo/go,polyverse-security/go,4ad/go,ImJasonH/go,odeke-em/go