test: do not negate test_path_is_* to assert absense

These tests use "! test_path_is_dir" or "! test_path_is_file" to
ensure that the path is not recursively checked out or "submodule
update" did not touch the working tree.

Use "test_path_is_missing" to assert that the path does not exist,
instead of negating test_path_is_* helpers; they are designed to be
loud in wrong occasions.  Besides, negating "test_path_is_dir" would
mean we would be happy if a file exists there, which is not the case
for these tests.

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

t/lib-submodule-update.sh

@@ -802,7 +802,7 @@ test_submodule_recursing_with_args_common () {
 			git branch -t no_submodule origin/no_submodule &&
 			$command no_submodule &&
 			test_superproject_content origin/no_submodule &&
-			! test_path_is_dir sub1 &&
+			test_path_is_missing sub1 &&
 			test_must_fail git config -f .git/modules/sub1/config core.worktree &&
 			test_must_fail git config -f .git/modules/sub1/modules/sub2/config core.worktree
 		)

t/t5572-pull-submodule.sh

@@ -121,7 +121,7 @@ test_expect_success "fetch.recurseSubmodules option triggers recursive fetch (bu
 	sub_oid=$(git -C child rev-parse HEAD) &&
 	git -C super/sub cat-file -e $sub_oid &&
 	# Check that the submodule worktree did not update
-	! test_path_is_file super/sub/merge_strategy_5.t
+	test_path_is_missing super/sub/merge_strategy_5.t
 '
 
 test_expect_success "fetch.recurseSubmodules takes precedence over submodule.recurse" '
@@ -134,7 +134,7 @@ test_expect_success "fetch.recurseSubmodules takes precedence over submodule.rec
 	sub_oid=$(git -C child rev-parse HEAD) &&
 	git -C super/sub cat-file -e $sub_oid &&
 	# Check that the submodule worktree did not update
-	! test_path_is_file super/sub/merge_strategy_6.t
+	test_path_is_missing super/sub/merge_strategy_6.t
 '
 
 test_expect_success 'pull --rebase --recurse-submodules (remote superproject submodule changes, local submodule changes)' '