virtio: vdpa: Fix reference count leak in octep_sriov_enable()

virtio: vdpa: Fix reference count leak in octep_sriov_enable()

pci_get_device() will increase the reference count for the returned
pci_dev, and also decrease the reference count for the input parameter
from if it is not NULL.

If we break the loop in  with 'vf_pdev' not NULL. We
need to call pci_dev_put() to decrease the reference count.

Found via static anlaysis and this is similar to commit c508eb042d97
("perf/x86/intel/uncore: Fix reference count leak in sad_cfg_iio_topology()")

Fixes: 8b6c724cdab8 ("virtio: vdpa: vDPA driver for Marvell OCTEON DPU devices")
Cc: stable@vger.kernel.org
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20251027060737.33815-1-linmq006@gmail.com>