PCI: endpoint: pci-epf-ntb: Remove duplicate resource teardown

PCI: endpoint: pci-epf-ntb: Remove duplicate resource teardown

epf_ntb_epc_destroy() duplicates the teardown that the caller is
supposed to do later. This leads to an oops when .allow_link fails or
when .drop_link is performed. Remove the helper.

Also drop pci_epc_put(). EPC device refcounting is tied to configfs EPC
group lifetime, and pci_epc_put() in the .drop_link path is sufficient.

Fixes: 8b821cf76150 ("PCI: endpoint: Add EP function driver to provide NTB functionality")
Signed-off-by: Koichiro Den <den@valinux.co.jp>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260226084142.2226875-3-den@valinux.co.jp