Update README.md per feedback (#39746)

Author: yufengwangca

examples/camera-controller/README.md

@@ -144,8 +144,14 @@ Terminal 1: Start the Camera App (Device)
 1. Launch the chip-camera-app binary. The --camera-deferred-offer flag prepares
    the camera to stream upon request from the controller.
 
+Clean up any existing configurations (first-time pairing only):
+
+```
+sudo rm -rf /tmp/chip_*
+```
+
 ```
-./out/linux-x64-camera-app/chip-camera-app --camera-deferred-offer
+./out/linux-x64-camera/chip-camera-app --camera-deferred-offer
 ```
 
 Terminal 2: Launch and Use the Camera Controller (Client)