CVE-2026-46069: wifi: mwifiex: fix use-after-free in mwifiex_adapter_cleanup()

In the Linux kernel, the following vulnerability has been resolved: wifi: mwifiex: fix use-after-free in mwifiex_adapter_cleanup() The mwifiex_adapter_cleanup() function uses timer_delete() (non-synchronous) for the wakeup_timer before the adapter structure is freed. This is incorrect because timer_delete() does not wait for any running timer callback to complete. If the wakeup_timer callback (wakeup_timer_fn) is executing when mwifiex_adapter_cleanup() is called, the callback will continue to access adapter fields (adapter->hw_status, adapter->if_ops.card_reset, etc.) which may be freed by mwifiex_free_adapter() called later in the mwifiex_remove_card() path. Use timer_delete_sync() instead to ensure any running timer callback has completed before returning.