ixgbevf: Fix resource leak in ixgbevf_init_module()

In the Linux kernel, the following vulnerability has been resolved: ixgbevf: Fix resource leak in ixgbevf_init_module() ixgbevf_init_module() won't destroy the workqueue created by create_singlethread_workqueue() when pci_register_driver() failed. Add destroy_workqueue() in fail path to prevent the resource leak. Similar to the handling of u132_hcd_init in commit f276e002793c ("usb: u132-hcd: fix resource leak")