transport: fix leaking negotiation tips

We do not free negotiation tips in the transport's smart options. Fix
this by freeing them on disconnect.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: pks-t

t/t5510-fetch.sh

@@ -5,6 +5,7 @@ test_description='Per branch config variables affects "git fetch".
 
 '
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-bundle.sh
 

transport.c

@@ -947,6 +947,10 @@ static int disconnect_git(struct transport *transport)
 		finish_connect(data->conn);
 	}
 
+	if (data->options.negotiation_tips) {
+		oid_array_clear(data->options.negotiation_tips);
+		free(data->options.negotiation_tips);
+	}
 	list_objects_filter_release(&data->options.filter_options);
 	oid_array_clear(&data->extra_have);
 	oid_array_clear(&data->shallow);