cmd/vet: update for new number formats [1.14 backport] #39288
Description
@ianlancetaylor requested issue #29986 to be considered for backport to the next 1.14 minor release.
@gopherbot Please open backport issues for 1.13 and 1.14
"go vet" should permit %O in fmt.Printf formats, as the formatting code was added in the 1.13 release.