Silence a use-after-free warning from the analyzer

The analyzer is known to be very conservative in the face of atomic
operations (e.g. https://bugs.llvm.org/show_bug.cgi?id=34365); this case
is no different.

It's concerned that `delete this;` might read a different value for
`flags`, and proceed to delete `refs`. Since there are many comments
explaining why this won't happen (and it all looks sane to me), use a
NOLINT to silence this warning.

Analyzer warning:
system/core/libutils/RefBase.cpp:445:5: warning: Use of memory after it
is freed

Bug: 27101951
Test: mma. Use-after-free warning is gone.
Change-Id: Ic1623971bd1bad546fbb12a79439116c89a6762d
diff --git a/libutils/RefBase.cpp b/libutils/RefBase.cpp
index 24737b9..f5f881f 100644
--- a/libutils/RefBase.cpp
+++ b/libutils/RefBase.cpp
@@ -442,6 +442,11 @@
     // and all accesses to refs happen before its deletion in the final decWeak.
     // The destructor can safely access mRefs because either it's deleting
     // mRefs itself, or it's running entirely before the final mWeak decrement.
+    //
+    // Since we're doing atomic loads of `flags`, the static analyzer assumes
+    // they can change between `delete this;` and `refs->decWeak(id);`. This is
+    // not the case. The analyzer may become more okay with this patten when
+    // https://bugs.llvm.org/show_bug.cgi?id=34365 gets resolved. NOLINTNEXTLINE
     refs->decWeak(id);
 }