tools/ccanlint: make sure _info compiles.

We used to crash, as reported by Stephen M. Cameron

Closes: #39
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

tools/ccanlint/tests/depends_accurate.c

@@ -137,7 +137,7 @@ struct ccanlint depends_accurate = {
 	.key = "depends_accurate",
 	.name = "Module's CCAN dependencies are the only CCAN files #included",
 	.check = check_depends_accurate,
-	.needs = "depends_exist test_depends_exist headers_idempotent"
+	.needs = "depends_exist info_compiles test_depends_exist headers_idempotent"
 };
 
 REGISTER_TEST(depends_accurate);

tools/ccanlint/tests/depends_exist.c

@@ -130,7 +130,7 @@ struct ccanlint depends_exist = {
 	.name = "Module's CCAN dependencies can be found",
 	.compulsory = true,
 	.check = check_depends_exist,
-	.needs = "info_exists"
+	.needs = "info_compiles"
 };
 
 REGISTER_TEST(depends_exist);

tools/ccanlint/tests/info_ported.c

@@ -39,7 +39,7 @@ struct ccanlint info_ported = {
 	.can_run = can_build,
 	.name = "_info indicates support for this platform",
 	.check = check_info_ported,
-	.needs = "info_exists"
+	.needs = "info_compiles"
 };
 
 REGISTER_TEST(info_ported);