accel/tcg: Pass last not end to page_collection_lock

accel/tcg: Pass last not end to page_collection_lock

Pass the address of the last byte to be changed, rather than
the first address past the last byte.  This avoids overflow
when the last page of the address space is involved.

Fixes a bug in the loop comparision where "<= end" would lock
one more page than required.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>