[dvsim] Fix summary table

When coverage isn't enabled results must not include a cell for coverage
results otherwise the summary table is misprinted.

Signed-off-by: Greg Chadwick <gac@lowrisc.org>
diff --git a/util/dvsim/SimCfg.py b/util/dvsim/SimCfg.py
index 3a3219e..e00b320 100644
--- a/util/dvsim/SimCfg.py
+++ b/util/dvsim/SimCfg.py
@@ -504,7 +504,7 @@
                 results_str += self.cov_report_deploy.cov_results
                 self.results_summary[
                     "Coverage"] = self.cov_report_deploy.cov_total
-            else:
+            elif self.cov:
                 self.results_summary["Coverage"] = "--"
 
             # append link of detail result to block name