AudioFlinger: Remove unnecessary friends

Remove obsolete TODOs, replace as needed with specific bug numbers.

Test: compiles
Bug: 288339104
Merged-In: Ied525f2f100203800f746239685e77b8e033618e
Change-Id: Ied525f2f100203800f746239685e77b8e033618e
diff --git a/services/audioflinger/AudioFlinger.cpp b/services/audioflinger/AudioFlinger.cpp
index 203af2f..276314c 100644
--- a/services/audioflinger/AudioFlinger.cpp
+++ b/services/audioflinger/AudioFlinger.cpp
@@ -3692,7 +3692,7 @@
          // clang-tidy suggests const ref
         sp<IAfEffectChain> ec = chains[i];  // NOLINT(performance-unnecessary-copy-initialization)
         int sessionid = ec->sessionId();
-        const auto t = sp<IAfThreadBase>::cast(ec->thread().promote()); // TODO(b/288339104)
+        const auto t = ec->thread().promote();
         if (t == 0) {
             continue;
         }