FileMap::create: remove duplicate addition. am: 54794ac613 am: 2912d9c190 am: 98e213207f am: a6d7150812

Original change: https://googleplex-android-review.googlesource.com/c/platform/system/core/+/12393457

Change-Id: I786693d6ba95669444f329a2f17c287d8fbc524e