t5516: drop NEEDSWORK about v2 reachability behavior

When this test was added in 6c301ad (fetch: do not pass ref-prefixes
for fetch by exact SHA1, 2018-05-31), there was still some uncertainty
about the v2 protocol's looser behavior with serving objects that are
not directly pointed at by a ref.

At this point that behavior is well established, and I do not think we
would ever change v2 to match the v0 behavior (and if we did,
remembering to update this test is the least of our concerns).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: peff

t/t5516-fetch-push.sh

@@ -1312,7 +1312,6 @@ test_expect_success 'fetch exact oid in protocol v2' '
 	test_must_fail git -C child cat-file -t $the_commit &&
 
 	# fetching the hidden object succeeds by default
-	# NEEDSWORK: should this match the v0 behavior instead?
 	git -C child fetch -v ../testrepo $the_commit:refs/heads/copy
 '