libfdt: fdt_path_offset_namelen: Reject empty paths am: d10c84c4bc am: 9f4834b735 am: e0440b0907 am: 13d00fad64 am: 7799b9fb26 am: 1c1c6e8948 am: ffd484022b am: 7aff1b1818

Original change: https://googleplex-android-review.googlesource.com/c/platform/external/dtc/+/20024811

Change-Id: I95fc3972f534116d066ed5b78b3648a4653bb3aa
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>