arcnet: Add NULL check in com20020pci_probe()

In the Linux kernel, the following vulnerability has been resolved: arcnet: Add NULL check in com20020pci_probe() devm_kasprintf() returns NULL when memory allocation fails. Currently, com20020pci_probe() does not check for this case, which results in a NULL pointer dereference. Add NULL check after devm_kasprintf() to prevent this issue and ensure no resources are left allocated.