This is required so that we give up the last reference to the device.
Removed the kfree() as put_device will result in release_pcie_device()
being called and hence the container of the device will be kfree'd.

[bhelgaas: fix conflict after my previous cleanup]
Signed-off-by: Levente Kurusa <levex@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>