binder: prevent kptr leak by using %pK format specifier

CVE-2016-6683

Works in conjunction with kptr_restrict.
Bug: 30143283

Change-Id: I3e74016ef0048867bc03e2ecfbb290ad9dc715a9
Tracked-On: https://jira01.devtools.intel.com/browse/AW-2264


Signed-off-by: Erwan Mahe <erwan.mahe@intel.com>
Reviewed-on: https://android.intel.com/545352


Reviewed-by: Dubray, SimonX <simonx.dubray@intel.com>
Reviewed-by: jenkins_ndg <jenkins_ndg@intel.com>
Reviewed-by: Tasayco Loarte, VictorX <victorx.tasayco.loarte@intel.com>
Reviewed-by: Maalem, Saadi <saadi.maalem@intel.com>