media: venus: hfi_cmds: struct hfi_session_release_buffer_pkt: Add __counted_by annotation

The only direct user of struct hfi_session_release_buffer_pkt is
pkt_session_unset_buffers() which sets "num_buffers" before using it
as a loop counter for accessing "buffer_info". Add the __counted_by
annotation to reflect the relationship.
Reviewed-by: Vikash Garodia <quic_vgarodia@quicinc.com>
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Reviewed-by: Dikshita Agarwal <quic_dikshita@quicinc.com>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20240710230914.3156277-2-kees@kernel.orgSigned-off-by: Kees Cook <kees@kernel.org>

drivers/media/platform/qcom/venus/hfi_cmds.h

@@ -227,7 +227,7 @@ struct hfi_session_release_buffer_pkt {
 	u32 extradata_size;
 	u32 response_req;
 	u32 num_buffers;
-	u32 buffer_info[];
+	u32 buffer_info[] __counted_by(num_buffers);
 };
 
 struct hfi_session_release_resources_pkt {