t1450: clean up sub-objects in duplicate-entry test

This test creates a multi-level set of trees, but its cleanup routine only removes the top-level tree. After the test finishes, the inner tree and the blob it points to remain, making the inner tree dangling. A later test ("cleaned up") verifies that we've removed any cruft and "git fsck" output is clean. This passes only because of a bug in git-fsck which fails to notice dangling trees. In preparation for fixing the bug, let's teach this earlier test to clean up after itself correctly. We have to remove the inner tree (and therefore the blob, too, which becomes dangling after removing that tree). Since the setup code happens inside a subshell, we can't just set a variable for each object. However, we can stuff all of the sha1s into the $T output variable, which is not used for anything except cleanup. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>