Fix result check of IBinder::pingBinder on vibrator HAl wrapper

The result is a status_t and should be checked agains the const values
listed in include/utils/Error.h.

Also adding error message to vibrator::HalResult to allow
vibrator::HalController to print underlying failure cause.

Bug: b/163027437
Test: atest libvibratorservice_test
Change-Id: Ic1c68246c401cd68a16a1d1f2d8e48d179441576