The check in "receive-pack" to prevent a checked out branch from
getting updated via updateInstead mechanism has been corrected.
* ps/receive-pack-updateinstead-in-worktree:
receive-pack: use worktree HEAD for updateInstead
t5516: clean up cloned and new-wt in denyCurrentBranch and worktrees test
t5516: test updateInstead with worktree and unborn bare HEAD