core/commands/unixfs/ls: Replace TODO context with command context

Discussing this on IRC ([1] through [2]), Jeromy and I decided that
we'd really like a way to configure per-command [3] and per-action
timeouts, but until we have that we want to leave the minute limit
here.  We also decided that the use of TODO here instead of the
per-command req.Context().Context was a bug, which I'm fixing with
this commit.

[1]: https://botbot.me/freenode/ipfs/2015-06-12/?msg=41714126&page=4
[2]: https://botbot.me/freenode/ipfs/2015-06-12/?msg=41715618&page=4
[3]: #1325

License: MIT
Signed-off-by: W. Trevor King <wking@tremily.us>

core/commands/unixfs/ls.go

@@ -94,7 +94,7 @@ directories, the child size is the IPFS link size.
 			case unixfspb.Data_Directory:
 				output[i].Links = make([]LsLink, len(merkleNode.Links))
 				for j, link := range merkleNode.Links {
-					getCtx, cancel := context.WithTimeout(context.TODO(), time.Minute)
+					getCtx, cancel := context.WithTimeout(ctx, time.Minute)
 					defer cancel()
 					link.Node, err = link.GetNode(getCtx, node.DAG)
 					if err != nil {