wifi: rtlwifi: destroy workqueue at rtl_deinit_core

wifi: rtlwifi: destroy workqueue at rtl_deinit_core

rtl_wq is allocated at rtl_init_core, so it makes more sense to destroy it
at rtl_deinit_core. In the case of USB, where _rtl_usb_init does not
require anything to be undone, that is fine. But for PCI, rtl_pci_init,
which is called after rtl_init_core, needs to deallocate data, but only if
it has been called.

That means that destroying the workqueue needs to be done whether
rtl_pci_init has been called or not. And since rtl_pci_deinit was doing it,
it has to be moved out of there.

It makes more sense to move it to rtl_deinit_core and have it done in both
cases, USB and PCI.

Since this is a requirement for a followup memory leak fix, mark this as
fixing such memory leak.

Fixes: 0c8173385e54 ("rtl8192ce: Add new driver")
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20241206173713.3222187-3-cascardo@igalia.com