ocxl: fix pci device refcount leak when calling get_function_0()

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: ocxl: fix pci device refcount leak when calling get_function_0() get_function_0() calls pci_get_domain_bus_and_slot(), as comment says, it returns a pci device with refcount increment, so after using it, pci_dev_put() needs be called. Get the device reference when get_function_0() is not called, so pci_dev_put() can be called in the error path and callers unconditionally. And add comment above get_dvsec_vendor0() to tell callers to call pci_dev_put().

References

• https://git.kernel.org/stable/c/a40e1b0a922a53fa925ea8b296e3de30a31ed028
• https://git.kernel.org/stable/c/37a13b274e4513c757e50c002ddcbf4bc89adbb2
• https://git.kernel.org/stable/c/9a1b3148975b71fdc194e62612478346bbe618cd
• https://git.kernel.org/stable/c/40ff4c2335a98f0ee96b099bfd70b8e6644f321f
• https://git.kernel.org/stable/c/27158c72678b39ee01cc01de1aba6b51c71abe2f