[PATCH v2] assert: Refactor assert/assert_perror

[Florian Weimer]

* Adhemerval Zanella Netto:

>> Why do we need __libc_message_nargs when things go into a varargs
>> function without an explicit argument count in the end anyway?
>
> This is the same logic from sysdep/unix/syscall.h, used on INLINE_SYSCALL_CALL,
> and it is required to correctly paste the argument is the expected order.  I
> think maybe there is a better way to accomplish it.

This is used for INLINE_SYSCALL_CALL etc. because the final target is
not variadic, but has a fixed number of arguments (loading only the
registers that are really required).  This isn't the case here as far as
I can see: the final function call is still variadic.

Thanks,
Florian