dpkg: Split post_script_tasks() debug message

Move the ensure_diversions debug progress message just before the
function call, to make this less confusing.

src/script.c

@@ -69,10 +69,10 @@ post_postinst_tasks(struct pkginfo *pkg, enum pkgstatus new_status)
 static void
 post_script_tasks(void)
 {
+	debug(dbg_triggersdetail, "post_script_tasks - ensure_diversions");
 	ensure_diversions();
 
-	debug(dbg_triggersdetail,
-	      "post_script_tasks - ensure_diversions; trig_incorporate");
+	debug(dbg_triggersdetail, "post_script_tasks - trig_incorporate");
 	trig_incorporate(modstatdb_get_status());
 }