MQDescriptor: warn about handle ownership

Ideally these should be explicit, but warning in the header for the
time being.

Bug: N/A
Test: N/A
Change-Id: I3596c6c0f6a1157ce859e29701686b06cce6aefe
diff --git a/base/include/hidl/MQDescriptor.h b/base/include/hidl/MQDescriptor.h
index a8a176b..0f61cb5 100644
--- a/base/include/hidl/MQDescriptor.h
+++ b/base/include/hidl/MQDescriptor.h
@@ -59,10 +59,12 @@
 
 template <typename T, MQFlavor flavor>
 struct MQDescriptor {
+    // Takes ownership of handle
     MQDescriptor(
             const std::vector<GrantorDescriptor>& grantors,
             native_handle_t* nHandle, size_t size);
 
+    // Takes ownership of handle
     MQDescriptor(size_t bufferSize, native_handle_t* nHandle,
                  size_t messageSize, bool configureEventFlag = false);