Revert back to always using *(int *)arg for now. While this
is incorrect, and causes endianness bugs on 64-bit big-endian
machines (sparc64), it's the best choice for now, as many of
these IOCTLs are used inside the kernel, and bogusly pass an
argument as "int *" which results in unaligned access panics
on sparc64 when attempting to dereference them via *(intptr_t *).

(Several of us are working on a real fix, which is uneasy.)