Use xmalloc in tst-setcontext-fpscr.c (bug 19668)

[Florian Weimer]

On 02/01/2018 09:37 PM, Joseph Myers wrote:
> -      auxv = (ElfW(auxv_t) *)malloc(getpagesize());
> +      auxv = (ElfW(auxv_t) *) xmalloc (getpagesize ());

This is okay, but you might as well drop the cast.

Thanks,
Florian