tcg: Replace region.end with region.total_size

A size is easier to work with than an end point,
particularly during initial buffer allocation.

Reviewed-by: Luis Pires <luis.pires@eldorado.org.br>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
1 file changed