data.go
func gogpgme_seekfunc(handle unsafe.Pointer, offset C.gpgme_off_t, whence C.int) C.gpgme_off_t {
	d := callbackLookup(uintptr(handle)).(*Data)
	n, err := d.s.Seek(int64(offset), int(whence))
	if err != nil {
		C.gpgme_err_set_errno(C.EIO)
		return -1
	}
	return C.gpgme_off_t(n)
}
func gogpgme_seekfunc(handle unsafe.Pointer, offset C.gpgme_off_t, whence C.int) C.gpgme_off_t {
	d := callbackLookup(uintptr(handle)).(*Data)
	n, err := d.s.Seek(int64(offset), int(whence))
	if err != nil {
		C.gpgme_err_set_errno(C.EIO)
		return -1
	}
	return C.gpgme_off_t(n)
}
//export gogpgme_seekfunc