media: rzv2h-ivc: Fix concurrent buffer list access

In the Linux kernel, the following vulnerability has been resolved: media: rzv2h-ivc: Fix concurrent buffer list access The list of buffers (`rzv2h_ivc::buffers.queue`) is protected by a spinlock (`rzv2h_ivc::buffers.lock`). However, in `rzv2h_ivc_transfer_buffer()`, which runs in a separate workqueue, the `list_del()` call is executed without holding the spinlock, which makes it possible for the list to be concurrently modified Fix that by removing a buffer from the list in the lock protected section. [assign ivc->buffers.curr in critical section as reported by Barnabas]