[automerge] libfdt: fdt_path_offset_namelen: Reject empty paths 2p: a6ac6d916d

Original change: https://googleplex-android-review.googlesource.com/c/platform/external/dtc/+/20024810

Bug: 246465319
Change-Id: I0ca57afacace494e41bb33cde3181437662e3547