adj_len_to_page doesn't return the correct result when the address
is already page aligned and the length is bigger than a page. Fix that.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Message-Id: <20170531220129.27724-20-aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>