t5550: break submodule config test into multiple sub-tests

Right now we test only the cloning case, but there are other
interesting cases (e.g., fetching). Let's pull the setup
bits into their own test, which will make things flow more
logically once we start adding more tests which use the
setup.

Let's also introduce some whitespace to the clone-test to
split the two parts: making sure it fails without our
cmdline config, and that it succeeds with it.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t5550-http-fetch-dumb.sh

@@ -91,17 +91,21 @@ test_expect_success 'configured username does not override URL' '
 	expect_askpass pass user@host
 '
 
-test_expect_success 'cmdline credential config passes into submodules' '
+test_expect_success 'set up repo with http submodules' '
 	git init super &&
 	set_askpass user@host pass@host &&
 	(
 		cd super &&
 		git submodule add "$HTTPD_URL/auth/dumb/repo.git" sub &&
 		git commit -m "add submodule"
-	) &&
+	)
+'
+
+test_expect_success 'cmdline credential config passes to submodule via clone' '
 	set_askpass wrong pass@host &&
 	test_must_fail git clone --recursive super super-clone &&
 	rm -rf super-clone &&
+
 	set_askpass wrong pass@host &&
 	git -c "credential.$HTTPD_URL.username=user@host" \
 		clone --recursive super super-clone &&