accel/tcg: Fix atomic_mmu_lookup for reads

accel/tcg: Fix atomic_mmu_lookup for reads

A copy-paste bug had us looking at the victim cache for writes.

Cc: qemu-stable@nongnu.org
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Fixes: 08dff435e2 ("tcg: Probe the proper permissions for atomic ops")
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20230505204049.352469-1-richard.henderson@linaro.org>
(cherry picked from commit 8c313254e61ed47a1bf4a2db714b25cdd94fbcce)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>