target-mips/helper.c:542: bad sizeof ?

Recent versions of gcc say this:

qemu/target-mips/helper.c:542:9: warning: ‘memset’ used with length equal to number of elements without multiplication by element size [-Wmemset-elt-size]

Source code is

   memset(env->CP0_WatchLo, 0, sizeof(*env->CP0_WatchLo));

Maybe better code

   memset(env->CP0_WatchLo, 0, 8 * sizeof(target_ulong));