runtime: simplify conditions testing g.paniconfault
runtime: simplify conditions testing g.paniconfault

Implement a comment by Ralph Corderoy on CL 29754.

Change-Id: I22bbede211ddcb8a057f16b4f47d335a156cc8d2
Reviewed-on: https://go-review.googlesource.com/29756
Run-TryBot: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>

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