Merge "HWC2: Clarify null client target handle" into nyc-dev am: 0154a6b08d
am: 1d61e380eb

* commit '1d61e380eb32f6dd7e846508032e9e501e10cd24':
  HWC2: Clarify null client target handle

Change-Id: I0a65bc0604ade6550190f4cdc6e523f02b25b1a1