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: [e-mail]
Signed-off-by: Miaoqian Lin <[e-mail]>
Signed-off-by: Michael S. Tsirkin <[e-mail]>
Message-Id: <[e-mail]>

drivers/vdpa/octeon_ep/octep_vdpa_main.c

···
 		octep_vdpa_assign_barspace(vf_pdev, pdev, index);
 		if (++index == num_vfs) {
 			done = true;
+			pci_dev_put(vf_pdev);
 			break;
 		}
 	}