"magic-trace run -trace-include-kernel true" failure

Tested with the following magic-trace versions:
- 5e8fdd3, built from source (output below is from testing this version)
- Version 1.0.2, 0a5dd46, downloaded from the releases page

Tested on Ubuntu 22.04, on an Intel i7-7700HQ processor.

Running without `-trace-include-kernel` succeeds:

```
$ _build/default/bin/magic_trace_bin.exe run true
[ perf record: Woken up 1 times to write data ]
[ Snapshot taken. ]
[ perf record: Captured and wrote 0.062 MB /tmp/magic_trace.tmp.09aec4/perf.data ]
[ Finished recording. ]
[ Decoding, this takes a while... ]
Warning: Debug info is unavailable, so filenames and line numbers will not be available in the trace.
See https://github.com/janestreet/magic-trace/wiki/Compiling-code-for-maximum-compatibility-with-magic-trace for more info.
Visit https://magic-trace.org/ and open trace.fxt to view trace.
```

Running with `-trace-include-kernel` fails:

```
$ sudo -s
root@ed-ubuntu-asus:/home/eddie/magic-trace# _build/default/bin/magic_trace_bin.exe run -trace-include-kernel true
[ Snapshot taken. ]
[ Finished recording. ]
[ Decoding, this takes a while... ]
Warning: Debug info is unavailable, so filenames and line numbers will not be available in the trace.
See https://github.com/janestreet/magic-trace/wiki/Compiling-code-for-maximum-compatibility-with-magic-trace for more info.
WARNING: The /tmp/magic_trace.tmp.6b36cb/perf.data/data file's data size field is 0 which is unexpected.
Was the 'perf record' command properly terminated?
(Unix.Exit (Exit_non_zero 255))
```

Start by reproducing the reported command on Ubuntu 22.04, comparing it with the successful run without kernel tracing. Inspect the magic-trace run entry point and the perf-recording and decoding output; done means -trace-include-kernel completes without the zero-size data error and produces a viewable trace.

Written by the indexing model from the issue text.