Replace all _LOG error calls with ALOGE.

The debuggerd code sometimes calls _LOG(..., logtype::ERROR, ...)
and sometimes ALOGE(). Standardize on ALOGE since the _LOG message
will wind up in the tombstone in weird places, but using ALOGE
will wind up in the logcat portion of the tombstone.

Bug: 21467089
Change-Id: Ie893f5e91d45b48ef3f5864c3a714e60ac848fb3