unit: allocate bus name match string on the stack

Let's use strjoina() rather than strjoin() for construct dbus match
strings.

Also, while we are at it, fix parameter ordering, so that our functions
always put the object first, like it is customary for OO-like
programming.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/core/dbus.c b/src/core/dbus.c
index 2d6a1ff836..d8891d49d8 100644
--- a/src/core/dbus.c
+++ b/src/core/dbus.c
@@ -777,7 +777,7 @@ static int bus_setup_api(Manager *m, sd_bus *bus) {
                 return r;
 
         HASHMAP_FOREACH_KEY(u, name, m->watch_bus, i) {
-                r = unit_install_bus_match(bus, u, name);
+                r = unit_install_bus_match(u, bus, name);
                 if (r < 0)
                         log_error_errno(r, "Failed to subscribe to NameOwnerChanged signal: %m");
         }