t2104: style fixes

We use tabs to indent, not two or four spaces.

These days, even the test fixture preparation should be done inside
test_expect_success block.

Address these two style violations in this test.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t2104-update-index-skip-worktree.sh

@@ -11,27 +11,27 @@ TEST_PASSES_SANITIZE_LEAK=true
 sane_unset GIT_TEST_SPLIT_INDEX
 
 test_set_index_version () {
-    GIT_INDEX_VERSION="$1"
-    export GIT_INDEX_VERSION
+	GIT_INDEX_VERSION="$1"
+	export GIT_INDEX_VERSION
 }
 
 test_set_index_version 3
 
-cat >expect.full <<EOF
-H 1
-H 2
-H sub/1
-H sub/2
-EOF
-
-cat >expect.skip <<EOF
-S 1
-H 2
-S sub/1
-H sub/2
-EOF
-
 test_expect_success 'setup' '
+	cat >expect.full <<-\EOF &&
+	H 1
+	H 2
+	H sub/1
+	H sub/2
+	EOF
+
+	cat >expect.skip <<-\EOF &&
+	S 1
+	H 2
+	S sub/1
+	H sub/2
+	EOF
+
 	mkdir sub &&
 	touch ./1 ./2 sub/1 sub/2 &&
 	git add 1 2 sub/1 sub/2 &&