livemedia-creator: Make sure ROOT_PATH exists (#1144140)

If ROOT_PATH doesn't exist when making a tar file, create it first.

Related: rhbz#1144140
(cherry picked from commit da68471b33)

src/sbin/livemedia-creator

@@ -640,6 +640,7 @@ def novirt_install(opts, disk_img, disk_size, repo_url):
         # Install directly into ROOT_PATH, make sure it starts clean
         if os.path.exists(ROOT_PATH):
             shutil.rmtree(ROOT_PATH)
+        if not os.path.isdir(ROOT_PATH):
             os.mkdir(ROOT_PATH)
     else:
         args += ["--image", disk_img]