repo: move daemon.lock -> repo.lock

The "daemon.lock" was really a repo.lock, as the cli also took it
and the purpose was any process mutex. This is part of the 1-to-2
migration, and has already been handled in
https://github.com/ipfs/fs-repo-migrations/tree/master/ipfs-1-to-2

repo/fsrepo/lock/lock.go

@@ -8,9 +8,9 @@ import (
 	"github.com/ipfs/go-ipfs/util"
 )
 
-// LockFile is the filename of the daemon lock, relative to config dir
+// LockFile is the filename of the repo lock, relative to config dir
 // TODO rename repo lock and hide name
-const LockFile = "daemon.lock"
+const LockFile = "repo.lock"
 
 func Lock(confdir string) (io.Closer, error) {
 	c, err := lock.Lock(path.Join(confdir, LockFile))