stackcount failure

Also I am trying the code listing in page 101 of the book "BPF Performance Tools". The code is,
```
stackcount -f -P -D 10 ktime_get > out.stackcount01.txt
```
A file named out.stackcount01.txt is created but it reads,
```
sequence item 1: expected str instance, bytes found
```
The OS is a SLES 15 SP1 with kernel version 4.12.14-197.34-default. The Python version is 3.6.10.

Start by reproducing the exact stackcount command from the issue on the reported SLES, kernel, and Python versions, then trace where its output handling produces the bytes/str error. Done means the command completes without the exception and out.stackcount01.txt contains the expected stack-count output.

Written by the indexing model from the issue text.