PCI: endpoint: Destroy the EPC device in devm_pci_epc_destroy()

The devm_pci_epc_destroy() comment says destroys the EPC device, but it
does not actually do that since devres_destroy() does not call
devm_pci_epc_release(), and it also can not fully undo what the API
devm_pci_epc_create() does, so it is faulty.

Fortunately, the faulty API has not been used by current kernel tree.  Use
devres_release() instead of devres_destroy() so the EPC device will be
released.

Link: https://lore.kernel.org/r/20241210-pci-epc-core_fix-v3-1-4d86dd573e4b@quicinc.com


Fixes: 5e8cb403 ("PCI: endpoint: Add EP core layer to enable EP controller and EP functions")
Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>