libfdt: fdt_path_offset_namelen: Reject empty paths am: d10c84c4bc am: 9f4834b735 am: e0440b0907 am: 13d00fad64 am: 7799b9fb26 am: 98ab028002 am: 0a053dfe49 am: 1716041baa

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

Change-Id: I37c1127c7b10f1152a5dbfe0155f7a4c36b9d5e5
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>