Fix USBTMC status byte interrupt buffer

Copy the READ_STATUS_BYTE interrupt payload into the class endpoint buffer before queuing the interrupt IN transfer. This keeps the buffer valid until the asynchronous transfer completes.

Fixes hathach#2928

Generated-by: OpenAI Codex
Signed-off-by: aineoae86-sys <ai.neo.ae86@gmail.com>

Author: aineoae86-sys

src/class/usbtmc/usbtmc_device.c

@@ -822,8 +822,9 @@ bool usbtmcd_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb_control_request
                       .bTag = bTag & 0x7Fu,
                   },
                   .StatusByte = tud_usbtmc_get_stb_cb(&(rsp.USBTMC_status))};
+          memcpy(usbtmc_epbuf.epnotif, &intMsg, sizeof(intMsg));
           // Must be queued before control request response sent (USB488v1.0 4.3.1.2)
-          usbd_edpt_xfer(rhport, usbtmc_state.ep_int_in, (void *) &intMsg, sizeof(intMsg), false);
+          usbd_edpt_xfer(rhport, usbtmc_state.ep_int_in, usbtmc_epbuf.epnotif, sizeof(intMsg), false);
         }
       } else {
         rsp.statusByte = tud_usbtmc_get_stb_cb(&(rsp.USBTMC_status));