internal/trace: fix a typo in error message
internal/trace: fix a typo in error message

Change-Id: Id79eaa6d49dae80c334c7243b0a5bbcdcb9397d3
Reviewed-on: https://go-review.googlesource.com/21758
Reviewed-by: Mikio Hara <e2f4d2eec1d9a1f781345cdd7260d7d52e6468ae@gmail.com>

golang/go,ImJasonH/go,codestation/go,ganboing/go-esx,linux-on-ibm-z/go,ganboing/go-esx,suncycheng/go,Cofyc/go,suncycheng/go,codestation/go,vsekhar/elastic-go,goodlang/good,Cofyc/go,golang/go,suncycheng/go,josharian/go,goodlang/good,suncycheng/go,4ad/go,momchil-velikov/go,linux-on-ibm-z/go,4ad/go,derekmarcotte/go,goodlang/good,vanloswang/go,vsekhar/elastic-go,ImJasonH/go,theif519/go,CAFxX/go,vanloswang/go,CAFxX/go,akutz/go,vanloswang/go,momchil-velikov/go,goodlang/good,polyverse-security/go,Cofyc/go,akutz/go,goodlang/good,cloudflare/go,ImJasonH/go,goodlang/good,4ad/go,vanloswang/go,vsekhar/elastic-go,josharian/go,CAFxX/go,josharian/go,golang/go,polyverse-security/go,josharian/go,josharian/go,momchil-velikov/go,polyverse-security/go,nawawi/go,akutz/go,vsekhar/elastic-go,ganboing/go-esx,cloudflare/go,vanloswang/go,linux-on-ibm-z/go,momchil-velikov/go,christopher-henderson/Go,suncycheng/go,derekmarcotte/go,cloudflare/go,theif519/go,4ad/go,ganboing/go-esx,suncycheng/go,Cofyc/go,golang/go,golang/go,golang/go,golang/go,derekmarcotte/go,momchil-velikov/go,golang/go,polyverse-security/go,akutz/go,nawawi/go,polyverse-security/go,derekmarcotte/go,nawawi/go,goodlang/good,CAFxX/go,ImJasonH/go,suncycheng/go,nawawi/go,cloudflare/go,ImJasonH/go,theif519/go,ImJasonH/go,Cofyc/go,4ad/go,cloudflare/go,4ad/go,linux-on-ibm-z/go,polyverse-security/go,codestation/go,codestation/go,linux-on-ibm-z/go,akutz/go,theif519/go,nawawi/go,vsekhar/elastic-go,ganboing/go-esx,CAFxX/go,Cofyc/go,josharian/go,codestation/go,josharian/go,4ad/go,theif519/go,derekmarcotte/go,CAFxX/go,vsekhar/elastic-go,cloudflare/go,cloudflare/go,4ad/go,theif519/go,polyverse-security/go,cloudflare/go,vanloswang/go,nawawi/go,ganboing/go-esx,josharian/go,ImJasonH/go,derekmarcotte/go,theif519/go,vanloswang/go,goodlang/good,codestation/go,Cofyc/go,codestation/go,linux-on-ibm-z/go,derekmarcotte/go,linux-on-ibm-z/go,CAFxX/go,theif519/go,linux-on-ibm-z/go,vsekhar/elastic-go,ImJasonH/go,nawawi/go,momchil-velikov/go,momchil-velikov/go,codestation/go,nawawi/go,ganboing/go-esx,Cofyc/go,vanloswang/go,akutz/go,ganboing/go-esx,akutz/go,CAFxX/go,akutz/go,momchil-velikov/go,polyverse-security/go,vsekhar/elastic-go,suncycheng/go,derekmarcotte/go