target/arm/ptw: Report stage 2 fault level for stage 2 faults on stage 1 ptw

target/arm/ptw: Report stage 2 fault level for stage 2 faults on stage 1 ptw

When we report faults due to stage 2 faults during a stage 1
page table walk, the 'level' parameter should be the level
of the walk in stage 2 that faulted, not the level of the
walk in stage 1. Correct the reporting of these faults.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230807141514.19075-15-peter.maydell@linaro.org