#1406 silently skipped the call to moveDirectory in case...

#1406 silently skipped the call to moveDirectory in case newBuildDir.isDirectory(), rather than throwing an IOE as renameTo does.
Also deleting apparently useless call to forceMkdir.

core/src/main/java/hudson/model/Job.java

@@ -654,8 +654,7 @@ public abstract class Job<JobT extends Job<JobT, RunT>, RunT extends Run<JobT, R
         File oldBuildDir = getBuildDir();
         super.movedTo(destination, newItem, destDir);
         File newBuildDir = getBuildDir();
-        if (oldBuildDir.isDirectory() && !newBuildDir.isDirectory()) {
-            FileUtils.forceMkdir(destDir.getParentFile());
+        if (oldBuildDir.isDirectory()) {
             FileUtils.moveDirectory(oldBuildDir, newBuildDir);
         }
     }