Malformed build tag
Reports malformed build tags and build tags in the incorrect location. The
go tool expects build tags to be located in particular places and follow a special syntax. If these requirements are not followed, build tags could either be ignored or the files could be incorrectly excluded from the build.
// +build ignore part should be before the package declaration. To fix that, you can apply the Place build tag before package quick-fix. After the quick-fix is applied: