media: venus: Use struct_size_t() helper in pkt_session_unset_buffers()

Prefer struct_size_t() over struct_size() when no pointer instance
of the structure type is present.

Signed-off-by: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Reviewed-by: Vikash Garodia <quic_vgarodia@quicinc.com>
Link: https://lore.kernel.org/r/ZKBfoqSl61jfpO2r@work
Signed-off-by: Kees Cook <keescook@chromium.org>

Author: GustavoARSilva

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

@@ -251,8 +251,8 @@ int pkt_session_unset_buffers(struct hfi_session_release_buffer_pkt *pkt,
 
 		pkt->extradata_size = 0;
 		pkt->shdr.hdr.size =
-			struct_size((struct hfi_session_set_buffers_pkt *)0,
-				    buffer_info, bd->num_buffers);
+			struct_size_t(struct hfi_session_set_buffers_pkt,
+				      buffer_info, bd->num_buffers);
 	}
 
 	pkt->response_req = bd->response_required;