logd: additional logging if read_offset > buffer_it->write_offset()

I didn't expect this to ever be hit, but apparently it is, so add
additional logging to track it down.

Bug: 168870781
Test: build
Change-Id: Ia472bc7458a3727e4d407365672f7394426ae515
diff --git a/logd/SerializedFlushToState.cpp b/logd/SerializedFlushToState.cpp
index 378cf20..fdf1dd3 100644
--- a/logd/SerializedFlushToState.cpp
+++ b/logd/SerializedFlushToState.cpp
@@ -91,7 +91,8 @@
         }
     } else {
         // read_offset > buffer_it->write_offset() should never happen.
-        CHECK(false);
+        LOG(FATAL) << "read_offset (" << read_offset << ") > buffer_it->write_offset() ("
+                   << buffer_it->write_offset() << ")";
     }
 }