tools/virtio: add krealloc_array

#include <linux/compiler.h>

#include <linux/types.h>

#include <linux/overflow.h>

#include <linux/list.h>

#include <linux/printk.h>

#include <linux/bug.h>

#  define unlikely(x)	(__builtin_expect(!!(x), 0))

# endif

static inline void *krealloc_array(void *p, size_t new_n, size_t new_size, gfp_t gfp)

{

	size_t bytes;

	if (unlikely(check_mul_overflow(new_n, new_size, &bytes)))

		return NULL;

	return krealloc(p, bytes, gfp);

}

#define pr_err(format, ...) fprintf (stderr, format, ## __VA_ARGS__)

#ifdef DEBUG

#define pr_debug(format, ...) fprintf (stderr, format, ## __VA_ARGS__)

#define dev_err(dev, format, ...) fprintf (stderr, format, ## __VA_ARGS__)

#define dev_warn(dev, format, ...) fprintf (stderr, format, ## __VA_ARGS__)

#define WARN_ON_ONCE(cond) (unlikely(cond) ? fprintf (stderr, "WARNING\n") : 0)

#define min(x, y) ({				\

	typeof(x) _min1 = (x);			\

	typeof(y) _min2 = (y);			\