s390/pci: Fix duplicate pci_dev_put() in disable_slot() when PF has child VFs

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: s390/pci: Fix duplicate pci_dev_put() in disable_slot() when PF has child VFs With commit bcb5d6c76903 ("s390/pci: introduce lock to synchronize state of zpci_dev's") the code to ignore power off of a PF that has child VFs was changed from a direct return to a goto to the unlock and pci_dev_put() section. The change however left the existing pci_dev_put() untouched resulting in a doubple put. This can subsequently cause a use after free if the struct pci_dev is released in an unexpected state. Fix this by removing the extra pci_dev_put().

References

• https://git.kernel.org/stable/c/c488f8b53e156d6dcc0514ef0afa3a33376b8f9e
• https://git.kernel.org/stable/c/957529baef142d95e0d1b1bea786675bd47dbe53
• https://git.kernel.org/stable/c/05a2538f2b48500cf4e8a0a0ce76623cc5bafcf1