Simplify the clone code. No update-ref needed.
Simplify the clone code. No update-ref needed.

perlpunk/git-subrepo,dzzh/git-subrepo,ingydotnet/git-subrepo,brijendratiwari/git-subrepo,stsquared99/git-subrepo,brijendratiwari/git-subrepo,dzzh/git-subrepo,stsquared99/git-subrepo,perlpunk/git-subrepo,ingydotnet/git-subrepo