sc-tracing: Only print events for whitelisted targets (paritytech#14487)

* sc-tracing: Only print events for whitelisted targets

We should only print events for whitelisted targets, otherwise we may run into some stack overflow
while printing the event.

* Update client/tracing/src/lib.rs

Co-authored-by: Koute <koute@users.noreply.github.com>

* Fix

---------

Co-authored-by: Koute <koute@users.noreply.github.com>

client/tracing/src/lib.rs

@@ -328,6 +328,10 @@ where
 	}
 
 	fn on_event(&self, event: &Event<'_>, ctx: Context<S>) {
+		if !self.check_target(event.metadata().target(), &event.metadata().level()) {
+			return
+		}
+
 		let parent_id = event.parent().cloned().or_else(|| {
 			if event.is_contextual() {
 				ctx.lookup_current().map(|span| span.id())