Input: sur40 - fix input device registration ordering

Input: sur40 - fix input device registration ordering

In sur40_probe(), input_register_device() was previously called early before
the V4L2 video device and vb2_queue components were fully initialized. If
userspace opened the input device immediately upon registration, sur40_open()
would trigger and start the sur40_poll() worker thread. This worker thread
invokes sur40_process_video() and accesses the uninitialized vb2_queue
structure, leading to a data race and potential system crash.

Furthermore, if V4L2 or video registration failed after input_register_device()
succeeded, the error path fell through to calling input_free_device() on a
successfully registered device instead of input_unregister_device(), corrupting
input core state.

Move input_register_device() to the very end of sur40_probe(). This ensures
the V4L2 and video queue structures are fully initialized before polling can
start, and naturally resolves the error path bug since input_free_device()
is now only called when input registration has not yet occurred.

To maintain strict LIFO (Last-In, First-Out) teardown ordering, also move
input_unregister_device() to the very beginning of sur40_disconnect(). This
guarantees that the input polling worker thread is stopped before V4L2
video components or control handlers are unregistered.

Reported-by: sashiko-bot@kernel.org
Cc: stable@vger.kernel.org
Assisted-by: Antigravity:gemini-3.5-flash
Link: https://patch.msgid.link/20260616051235.1549517-1-dmitry.torokhov@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>