fixes some (not all) buffer overreads during decoding pentax makernote entries. am: 836cfdb99e am: 0a45dca22e am: 24bdc1361a am: 8e051e1ef6 am: 3dcd0f5c7e am: 514b69b2a6 am: 2769ec9913 am: cd54138907 am: ec9ac7b9c5

Original change: https://googleplex-android-review.googlesource.com/c/platform/external/libexif/+/12970376

Change-Id: Ic441e8011da33010c3d9f5ae0ca0024782e95425