crypto: nx - Fix packed layout in struct nx842_crypto_header

crypto: nx - Fix packed layout in struct nx842_crypto_header

struct nx842_crypto_header is declared with the __packed attribute,
however	the fields grouped with struct_group_tagged() were not packed.
This caused the grouped header portion of the structure to lose the
packed layout guarantees of the containing structure.

Fix this by replacing struct_group_tagged() with __struct_group(...,
..., __packed, ...) so the grouped fields are packed, and the original
layout is preserved, restoring the intended packed layout of the
structure.

Before changes:
struct nx842_crypto_header {
	union {
		struct {
			__be16     magic;                /*     0     2 */
			__be16     ignore;               /*     2     2 */
			u8         groups;               /*     4     1 */
		};                                       /*     0     6 */
		struct nx842_crypto_header_hdr hdr;      /*     0     6 */
	};                                               /*     0     6 */
	struct nx842_crypto_header_group group[];        /*     6     0 */

	/* size: 6, cachelines: 1, members: 2 */
	/* last cacheline: 6 bytes */
} __attribute__((__packed__));

After changes:
struct nx842_crypto_header {
	union {
		struct {
			__be16     magic;                /*     0     2 */
			__be16     ignore;               /*     2     2 */
			u8         groups;               /*     4     1 */
		} __attribute__((__packed__));           /*     0     5 */
		struct nx842_crypto_header_hdr hdr;      /*     0     5 */
	};                                               /*     0     5 */
	struct nx842_crypto_header_group group[];        /*     5     0 */

	/* size: 5, cachelines: 1, members: 2 */
	/* last cacheline: 5 bytes */
} __attribute__((__packed__));

Fixes: 1e6b251ce175 ("crypto: nx - Avoid -Wflex-array-member-not-at-end warning")
Cc: stable@vger.kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>