libbinder: remove stale blocking TODO

We have shutdown triggers now, so it's not a concern.

Bug: 186470974
Test: N/A
Change-Id: I3d8319d3895def94d03f5588899058718bc7d5d6
diff --git a/libs/binder/RpcSession.cpp b/libs/binder/RpcSession.cpp
index 7565f1b..50a30cc 100644
--- a/libs/binder/RpcSession.cpp
+++ b/libs/binder/RpcSession.cpp
@@ -500,7 +500,6 @@
 
     // TODO(b/189955605): we should add additional sessions dynamically
     // instead of all at once.
-    // TODO(b/186470974): first risk of blocking
     size_t numThreadsAvailable;
     if (status_t status = getRemoteMaxThreads(&numThreadsAvailable); status != OK) {
         ALOGE("Could not get max threads after initial session setup: %s",