nodedev: mdev: Report an error when mdev path resolution fails

It might happen that virFileResolveLinkHelper fails on the lstat system
call. virFileResolveLink expects the caller to report an error when it
fails, however this wasn't the case for udevProcessMediatedDevice.
Signed-off-by: NErik Skultety <eskultet@redhat.com>

src/node_device/node_device_udev.c

@@ -1121,8 +1121,10 @@ udevProcessMediatedDevice(struct udev_device *dev,
     if (virAsprintf(&linkpath, "%s/mdev_type", udev_device_get_syspath(dev)) < 0)
         goto cleanup;
 
-    if (virFileResolveLink(linkpath, &canonicalpath) < 0)
+    if (virFileResolveLink(linkpath, &canonicalpath) < 0) {
+        virReportSystemError(errno, _("failed to resolve '%s'"), linkpath);
         goto cleanup;
+    }
 
     if (VIR_STRDUP(data->type, last_component(canonicalpath)) < 0)
         goto cleanup;