[Checkers] Vararg syntax

[Michael Ernst]

Mahmood-

> I interpreted the vararg syntax in a similar manner to arrays, so
>    @Nullable String ... a1;  // a1 is nonnull array of nullable string, like @Nullable String []
>    String @Nullable ... a2;  // a2 is nullable array of nonnull string, like String @Nullable []

You is correct.  I'm not sure whether I was confused, or there was some
conflating error at the same line.  In any event, I'll check in a clearer
test if I continue to have trouble.

                    -Mike