don't assume reloc_addr passed to elf_machine_rel* is aligned

[Roland McGrath]

> The patch below renames the reloc_addr argument to reloc_addr_arg,
> while changing its type to void*, and re-introduces reloc_addr as a
> variable of the original type in functions that still reference the
> original type.  This is what the original patch did, except that the
> argument is now named reloc_addr_arg, instead of just reloc_addr_.

This patch looks fine to me.  Have you tested it on at least some
reasonable set of machines?