fscrypt: Fix Data Unit Number used in file encryption

struct fscrypt_ctx;

/* iv sector for security/pfe/pfk_fscrypt.c and f2fs. sizeof is required

 * to accommodate 32 bit targets.

 */

/* iv sector for security/pfe/pfk_fscrypt.c and f2fs */

#define PG_DUN(i, p)                                            \

	((((i)->i_ino & 0xffffffff) << (sizeof((i)->i_ino)/2)) | \

				((p)->index & 0xffffffff))

	(((((u64)(i)->i_ino) & 0xffffffff) << 32) | ((p)->index & 0xffffffff))

struct fscrypt_info;