util: Fixing invalid error checking from virPCIGetNetname()

The @linkdev is In/Out function parameter as second order
reference pointer so requires first order dereference for
checking NULL which can be the result of virPCIGetNetName().

Fixes: d6ee56d7 (util: change virPCIGetNetName() to not return error if device has no net name)
Signed-off-by: NRadoslaw Biernacki <radoslaw.biernacki@linaro.org>
Signed-off-by: Ndann frazier <dann.frazier@canonical.com>

src/util/virhostdev.c

@@ -314,7 +314,7 @@ virHostdevNetDevice(virDomainHostdevDefPtr hostdev,
         if (virPCIGetNetName(sysfs_path, 0, NULL, linkdev) < 0)
             return -1;
 
-        if (!linkdev) {
+        if (!(*linkdev)) {
             virReportError(VIR_ERR_INTERNAL_ERROR,
                            _("The device at %s has no network device name"),
                            sysfs_path);