strconv: fix initialization of atofRandomTests
strconv: fix initialization of atofRandomTests

The init func was using testing.Short, but that's not available
until after flag parsing. Found by CL 49251.

Change-Id: Ia7b871043375260873fa2c7e81e1d43c1c83d33f
Reviewed-on: https://go-review.googlesource.com/49253
Run-TryBot: Russ Cox <5ad239cb8a44f659eaaee0aa1ea5b94947abe557@golang.org>
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>

akutz/go,CAFxX/go,akutz/go,Cofyc/go,codestation/go,polyverse-security/go,cloudflare/go,CAFxX/go,cloudflare/go,golang/go,nawawi/go,josharian/go,cloudflare/go,josharian/go,codestation/go,vsekhar/elastic-go,josharian/go,akutz/go,Cofyc/go,josharian/go,golang/go,cloudflare/go,josharian/go,vsekhar/elastic-go,nawawi/go,akutz/go,Cofyc/go,polyverse-security/go,CAFxX/go,codestation/go,CAFxX/go,CAFxX/go,CAFxX/go,josharian/go,golang/go,Cofyc/go,nawawi/go,akutz/go,CAFxX/go,polyverse-security/go,cloudflare/go,polyverse-security/go,nawawi/go,christopher-henderson/Go,CAFxX/go,Cofyc/go,vsekhar/elastic-go,nawawi/go,codestation/go,Cofyc/go,akutz/go,vsekhar/elastic-go,golang/go,codestation/go,golang/go,golang/go,nawawi/go,codestation/go,polyverse-security/go,josharian/go,Cofyc/go,golang/go,vsekhar/elastic-go,akutz/go,nawawi/go,golang/go,vsekhar/elastic-go,cloudflare/go,vsekhar/elastic-go,polyverse-security/go,josharian/go,vsekhar/elastic-go,polyverse-security/go,codestation/go,cloudflare/go,akutz/go,Cofyc/go,polyverse-security/go,cloudflare/go,codestation/go,nawawi/go