attr: remove index from git_attr_set_direction()

diff --git a/t/t1003-read-tree-prefix.sh b/t/t1003-read-tree-prefix.sh
index 8c6d67edda1468ba0f1c7afc6d13ea3a7bbe0a90..b6111cd150fdd69973142808cf4a86a4fa6b7e76 100755 (executable)
--- a/t/t1003-read-tree-prefix.sh
+++ b/t/t1003-read-tree-prefix.sh
@@ -11,7 +11,7 @@ test_description='git read-tree --prefix test.
 test_expect_success setup '
        echo hello >one &&
        git update-index --add one &&
-       tree=`git write-tree` &&
+       tree=$(git write-tree) &&
        echo tree is $tree
 '