crypto: qat - Annotate struct adf_fw_counters with __counted_by

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct adf_fw_counters.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Tom Rix <trix@redhat.com>
Cc: Adam Guerin <adam.guerin@intel.com>
Cc: Lucas Segarra Fernandez <lucas.segarra.fernandez@intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: qat-linux@intel.com
Cc: linux-crypto@vger.kernel.org
Cc: llvm@lists.linux.dev
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Acked-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/intel/qat/qat_common/adf_fw_counters.c

@@ -34,7 +34,7 @@ struct adf_ae_counters {
 
 struct adf_fw_counters {
 	u16 ae_count;
-	struct adf_ae_counters ae_counters[];
+	struct adf_ae_counters ae_counters[] __counted_by(ae_count);
 };
 
 static void adf_fw_counters_parse_ae_values(struct adf_ae_counters *ae_counters, u32 ae,