libqcomui: Add null check for incoming buffer

Add null check for incoming buffer in updateBufferS3DFormat function.
return invalid value if buffer is NULL

Change-Id: I97c535ae7291ee12648a92bff843c0c500bce4df
(cherry picked from commit e009dff7644d9b0663f3939e48ad1e955b1f76b5)

Conflicts:

	libqcomui/qcom_ui.cpp

libqcomui/qcom_ui.cpp

@@ -321,6 +321,21 @@ int updateBufferGeometry(sp<GraphicBuffer> buffer, const qBufGeometry updatedGeo
     return 0;
 }
 
+/* Update the S3D format of this buffer.
+*
+* @param: buffer whosei S3D format needs to be updated.
+* @param: Updated buffer S3D format
+*/
+int updateBufferS3DFormat(sp<GraphicBuffer> buffer, const int s3dFormat)
+{
+    if (buffer == 0) {
+        LOGE("%s: graphic buffer is NULL", __FUNCTION__);
+        return -EINVAL;
+    }
+
+    buffer->format |= s3dFormat;
+    return 0;
+}
 /*
  * Updates the flags for the layer
  *