Set permissions on the initrd (#863018)

Dracut now makes the initrd with 600 permissions
for security reasons. These reasons do not apply
to install images, and we want the other tools
that use lorax to be able to read the initrd file.

src/pylorax/ltmpl.py

@@ -302,6 +302,7 @@ class LoraxTemplateRunner(object):
           Same as installkernel, but for "initrd".
         '''
         self.install(src, dest)
+        self.chmod(dest, '644')
         self.treeinfo(section, "initrd", dest)
 
     def hardlink(self, src, dest):