merge.applyupdates: don't return early if merge driver's conclude failed

Somewhat silly oversight -- this prevented the progress bar from being reset.

mercurial/merge.py

@@ -1014,7 +1014,7 b' def applyupdates(repo, actions, wctx, mc'
         if not driverconclude(repo, ms, wctx, labels=labels):
             # XXX setting unresolved to at least 1 is a hack to make sure we
             # error out
-            return updated, merged, removed, max(unresolved, 1)
+            unresolved = max(unresolved, 1)
 
         ms.commit()