CVE-2025-37974 s390/pci: Fix missing check for zpci_create_device() error return

In the Linux kernel, the following vulnerability has been resolved: s390/pci: Fix missing check for zpcicreatedevice error return The zpcicreatedevice function returns an error pointer that needs to be checked before dereferencing it as a struct zpcidev pointer. Add the missing check in clpadd...