filter-repo: fix comments in _parse_literal_command

Signed-off-by: Elijah Newren <newren@gmail.com>

git-filter-repo

@@ -1586,13 +1586,13 @@ class FastExportFilter(object):
 
   def _parse_literal_command(self):
     """
-    Parse literal command.  Just dump the line as is.
+    Parse literal command.  Then just dump the line as is.
     """
     # Create the literal command object
     command = LiteralCommand(self._currentline)
     self._advance_currentline()
 
-    # Now print the resulting checkpoint
+    # Now print the resulting literal command
     if not command.dumped:
       command.dump(self._output)