tools/rtla: Improve code readability in timerlat_load.py

The enhancements made to timerlat_load.py are intended to improve the
script's robustness and readability.

Summary of the changes:
- Unnecessary semicolons at the end of lines have been removed.
- Parentheses surrounding the if statement checking args.prio have been
eliminated.
- String concatenation for constructing timerlat_path has been replaced
with an f-string.
- Spacing in a multiplication expression has been adjusted for improved
clarity.

Cc: "jkacur@redhat.com" <jkacur@redhat.com>
Cc: "lgoncalv@redhat.com" <lgoncalv@redhat.com>
Link: https://lore.kernel.org/j2B-ted7pv3TaldTyqfIHrMmjq2fVyBFgnu3TskiQJsyRzy9loPTVVJoqHnrCWu5T88MDIFc612jUglH6Sxkdg9LN-I1XuITmoL70uECmus=@protonmail.com


Signed-off-by: Furkan Onder <furkanonder@protonmail.com>
Reviewed-by: Tomas Glozar <tglozar@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>