media: venus: hfi: avoid null dereference in deinit

In the Linux kernel, the following vulnerability has been resolved: media: venus: hfi: avoid null dereference in deinit If venus_probe fails at pm_runtime_put_sync the error handling first calls hfi_destroy and afterwards hfi_core_deinit. As hfi_destroy sets core->ops to NULL, hfi_core_deinit cannot call the core_deinit function anymore. Avoid this null pointer derefence by skipping the call when necessary.