Tracing tooling updates for 6.8-rc4

RTLA:
        - rtla tools are exiting with a positive value  when usage()
          is called. Make them return 0 if the usage was called via
          -h/--help.

        - the -P priority sets the sched priority for rtla workload.
          When the SCHED_OTHER scheduler is selected, it sets
          the rt_priority instead of the nice parameter. Setting
          the nice value is the correct thing, so fix it.

        - rtla is failing to compile with clang due to unsupported
          options from gcc. Adjusting the compiler/linker options
          makes clang work properly.

        - Remove the sched_getattr() unused function on utils.c.

        - Fixes on variable initialization and size, reported by
          clang.

Verification:
        - rv is failing to compile with clang due to unsupported
          options from gcc. Adjusting the compiler/linker options
          makes clang work properly.

        - Fix an uninitialized variable on in_kernel.c reported by
          clang.
tools/rtla: Exit with EXIT_SUCCESS when help is invoked

Fix rtla so that the following commands exit with 0 when help is invoked

rtla osnoise top -h
rtla osnoise hist -h
rtla timerlat top -h
rtla timerlat hist -h

Link: https://lore.kernel.org/linux-trace-devel/20240203001607.69703-1-jkacur@redhat.com

Cc: stable@vger.kernel.org
Fixes: 1eeb6328e8b3 ("rtla/timerlat: Add timerlat hist mode")
Signed-off-by: John Kacur <jkacur@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
4 files changed