After "git checkout -b '漢字'" to create a branch with UTF-8
character in it, "gitk" shows the branch name incorrectly, as it
forgets to turn the bytes read from the "git show-ref" command
into Unicode characters.
Signed-off-by: Kazuhiro Kato <kato-k@ksysllc.co.jp>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>