BufferHub{Buffer,Metadata}: Some other minor changes

1/ Move BufferHubMetadata out of android::dvr namespace
2/ Fix some misnamed variables

Bug: 111976433
Test: BufferHubBuffer_test
Change-Id: I06ec1c3cc4831c865b672680b49adb006d6e1835
diff --git a/libs/ui/BufferHubBuffer.cpp b/libs/ui/BufferHubBuffer.cpp
index 606386c..2696c6c 100644
--- a/libs/ui/BufferHubBuffer.cpp
+++ b/libs/ui/BufferHubBuffer.cpp
@@ -41,7 +41,6 @@
 
 #include <poll.h>
 
-using android::dvr::BufferHubMetadata;
 using android::dvr::BufferTraits;
 using android::dvr::DetachedBufferRPC;
 using android::dvr::NativeHandleWrapper;
@@ -160,7 +159,7 @@
 
     // If all imports succeed, replace the previous buffer and id.
     mId = bufferId;
-    mBfferStateBit = bufferTraits.buffer_state_bit();
+    mBufferStateBit = bufferTraits.buffer_state_bit();
 
     // TODO(b/112012161) Set up shared fences.
     ALOGD("BufferHubBuffer::ImportGraphicBuffer: id=%d, buffer_state=%" PRIx64 ".", id(),