Increase coverage score

CI complains not only when the score is too low but also when it is
too high.  Accommodate the increased average coverage caused by adding
vhost-device-scmi and its unit tests.

Signed-off-by: Milan Zamazal <[email protected]>

Author: mz-pdm

coverage_config_x86_64.json

@@ -1,5 +1,5 @@
 {
-  "coverage_score": 68.2,
+  "coverage_score": 71.0,
   "exclude_path": "",
   "crate_features": ""
 }