accel/tcg: Adjust probe_access call to page_check_range

accel/tcg: Adjust probe_access call to page_check_range

We have validated that addr+size does not cross a page boundary.
Therefore we need to validate exactly one page.  We can achieve
that passing any value 1 <= x <= size to page_check_range.

Passing 1 will simplify the next patch.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200508154359.7494-5-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>