rpk: missing new line in generated script in rpk redpanda tune

[r-vasquez]

Version & Environment

Redpanda version: (use rpk version):

Version:     v23.3.1
Git ref:     ce417018bf
Build date:  2023-12-22T15:50:55Z
OS/Arch:     linux/amd64
Go version:  go1.21.3

What went wrong?

When generating a tunning script using rpk redpanda tune all --output-script we get:

$ rpk redpanda tune all --output-script /tmp/tune-all-script
$ cat /tmp/tune-all-script
#!/bin/bash

# Redpanda Tuning Script
# ----------------------------------
# This file was autogenerated by RPK

truncate -s 1000000000 /var/lib/redpanda/data/ballastecho 'performance' > /sys/devices/system/cpu/cpufreq/policy0/scaling_governor
echo 'performance' > /sys/devices/system/cpu/cpufreq/policy1/scaling_governor
echo 'performance' > /sys/devices/system/cpu/cpufreq/policy2/scaling_governor 

There is a missing newline in the line that contains truncate:

truncate -s 1000000000 /var/lib/redpanda/data/ballastecho 'performance' > /sys/devices/system/cpu/cpufreq/policy0/scaling_governor

What should have happened instead?

Each command should be in a separate line.

How to reproduce the issue?

1. rpk redpanda mode prod
2. rpk redpanda tune all --output-script /tmp/tune-all-script
3. cat /tmp/tune-all-script

Additional information

Please attach any relevant logs, backtraces, or metric charts.