wfx_hif_req_start_scan_alt
size_t buf_len = sizeof(struct wfx_hif_req_start_scan_alt) + sizeof(u8);
struct wfx_hif_req_start_scan_alt *body = wfx_alloc_hif(buf_len, &hif);
size_t buf_len = sizeof(struct wfx_hif_req_start_scan_alt) + chan_num * sizeof(u8);
struct wfx_hif_req_start_scan_alt *body = wfx_alloc_hif(buf_len, &hif);