tools: Fix small bug in ProtoFileToDotProto am: a5221eeff1
tools: Fix small bug in ProtoFileToDotProto am: a5221eeff1

Original change: https://android-review.googlesource.com/c/platform/external/perfetto/+/1775025

Change-Id: I2f4cb0e6eed0298494c2ffe7e98e234c3e5eb2bc

google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto