Small fix to hardlinking to deal with Joliet.

pylint pointed out that we weren't necessarily
handling all situations, which isn't quite true.
Nevertheless, it is easy enough for us to change
this and slightly improve performance along the way.

Signed-off-by: Chris Lalancette <clalancette@gmail.com>

pycdlib/pycdlib.py

@@ -3102,16 +3102,16 @@ def _add_hard_link_to_inode(self, data_ino, length, file_mode,
                 vd = self.pvd
                 rr = self.rock_ridge
                 xa = self.xa
-            elif joliet_new_path is not None:
+            else:
+                # Above we checked to make sure we got exactly one new path, so
+                # we know for certain that this is Joliet.
                 if self.joliet_vd is None:
                     raise pycdlibexception.PyCdlibInternalError('Tried to link to Joliet record on non-Joliet ISO')
                 # ... to a file on the Joliet filesystem.
                 (new_name, new_parent) = self._joliet_name_and_parent_from_path(joliet_new_path)
                 vd = self.joliet_vd
                 rr = ''
                 xa = False
-            # Above we checked to make sure we got at least one new path, so we
-            # don't need to worry about the else situation here.
 
             new_rec = dr.DirectoryRecord()
             new_rec.new_file(vd, length, new_name, new_parent,