bisect: use verbatim commit subject in the bisect log

Due to a typo, the commit subject was shell expanded in the bisect log.
That is, if you had some shell pattern in the commit subject, bisect
would happily put all matching file names into the log.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Tested-by: Frans Pop <elendil@planet.nl>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-bisect.sh

@@ -135,7 +135,7 @@ bisect_write() {
 		*)		die "Bad bisect_write argument: $state" ;;
 	esac
 	git update-ref "refs/bisect/$tag" "$rev"
-	echo "# $state: "$(git show-branch $rev) >>"$GIT_DIR/BISECT_LOG"
+	echo "# $state: $(git show-branch $rev)" >>"$GIT_DIR/BISECT_LOG"
 	test -z "$nolog" && echo "git-bisect $state $rev" >>"$GIT_DIR/BISECT_LOG"
 }