exfat: use EXT4_SUPER_MAGIC in magic.h

#include <linux/ratelimit.h>

#include <linux/nls.h>

#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 17, 0)

#include <linux/magic.h>

#else

#define EXFAT_SUPER_MAGIC       0x2011BAB0UL

#endif

#define EXFAT_VERSION		"5.14.1"

#define EXFAT_SUPER_MAGIC       0x2011BAB0UL

#define EXFAT_ROOT_INO		1

#define EXFAT_CLUSTERS_UNTRACKED (~0u)