target-arm: Fix typo in ARM946 cp15 c5 handling

Fix a typo in handling of the ARM946 cp15 c5 c0 0 1 handling
(instruction access permission bits) that meant it would
return the data access permission bits by mistake.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

target-arm/helper.c

@@ -2025,7 +2025,7 @@ uint32_t HELPER(get_cp15)(CPUARMState *env, uint32_t insn)
             return env->cp15.c5_data;
         case 1:
             if (arm_feature(env, ARM_FEATURE_MPU))
-                return simple_mpu_ap_bits(env->cp15.c5_data);
+                return simple_mpu_ap_bits(env->cp15.c5_insn);
             return env->cp15.c5_insn;
         case 2:
             if (!arm_feature(env, ARM_FEATURE_MPU))