Fix a clang-analyzer-cplusplus.NewDelete warning.

This fixes warning: Argument to 'delete' is the address of the local
variable 'inBuffer', which is not memory allocated by 'new'
[clang-analyzer-cplusplus.NewDelete]

Bug: none
Test: The warning is gone.
Change-Id: I6c954a679ba22e0d7859caaafce24f4e50b0391d
diff --git a/services/audioflinger/Tracks.cpp b/services/audioflinger/Tracks.cpp
index 4c48e8b..9cab4c7 100644
--- a/services/audioflinger/Tracks.cpp
+++ b/services/audioflinger/Tracks.cpp
@@ -1336,7 +1336,9 @@
             if (mBufferQueue.size()) {
                 mBufferQueue.removeAt(0);
                 free(pInBuffer->mBuffer);
-                delete pInBuffer;
+                if (pInBuffer != &inBuffer) {
+                    delete pInBuffer;
+                }
                 ALOGV("OutputTrack::write() %p thread %p released overflow buffer %zu", this,
                         mThread.unsafe_get(), mBufferQueue.size());
             } else {