Re: [PATCH v2 5/5] cache-tree: avoid an unnecessary check

"Johannes Schindelin via GitGitGadget" [off-list ref]
writes:

From: Johannes Schindelin <redacted>

The first thing the `parse_tree()` function does is to return early if
the tree has already been parsed. Therefore we do not need to guard the
`parse_tree()` call behind a check of that flag.

Makes sense, and it doubly makes sense to keep this separate from
the change done to the same location in [4/5].

Will queue.