Fix libgui cts crash bug

While enabling #define LOG_NDEBUG 0, run camera cts test command:
run cts -m CtsCameraTestCases -t android.hardware.camera2.cts.MultiViewTest#testSharedSurfaceImageReaderSwitch
the libgui will crash due to nullptr, fix this by add nullptr
judgement when pointing to the Graphicbuffer handle
Bug: 228349805

Signed-off-by: tangcheng <tangcheng@xiaomi.com>
Change-Id: I69a84bdb5208b16df88f5f09f45c1a93ad2afe01
diff --git a/libs/gui/BufferQueueProducer.cpp b/libs/gui/BufferQueueProducer.cpp
index 5fe5e71..2d56dd3 100644
--- a/libs/gui/BufferQueueProducer.cpp
+++ b/libs/gui/BufferQueueProducer.cpp
@@ -606,7 +606,8 @@
     BQ_LOGV("dequeueBuffer: returning slot=%d/%" PRIu64 " buf=%p flags=%#x",
             *outSlot,
             mSlots[*outSlot].mFrameNumber,
-            mSlots[*outSlot].mGraphicBuffer->handle, returnFlags);
+            mSlots[*outSlot].mGraphicBuffer != nullptr ?
+            mSlots[*outSlot].mGraphicBuffer->handle : nullptr, returnFlags);
 
     if (outBufferAge) {
         *outBufferAge = mCore->mBufferAge;