runtime: remove redundant expression from SetFinalizer
runtime: remove redundant expression from SetFinalizer

The previous if condition already checks the same expression and doesn't
have side effects.

Change-Id: Ieaf30a786572b608d0a883052b45fd3f04bc6147
Reviewed-on: https://go-review.googlesource.com/28475
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>
Run-TryBot: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>

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