runtime: fix case in KeepAlive comment
runtime: fix case in KeepAlive comment

Fixes #16299.

Change-Id: I76f541c7f11edb625df566f2f1035147b8bcd9dd
Reviewed-on: https://go-review.googlesource.com/24830
Run-TryBot: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>

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