perf test: Skip perf trace tests when running as non-root

perf trace requires root because it needs to use tracepoints and BPF.
Skip those test when it's not run as root.

Before:
  $ perf test trace
   15: Parse sched tracepoints fields                                  : Skip (permissions)
   80: perf ftrace tests                                               : Skip
  105: perf trace enum augmentation tests                              : FAILED!
  106: perf trace BTF general tests                                    : FAILED!
  107: perf trace exit race                                            : FAILED!
  118: probe libc's inet_pton & backtrace it with ping                 : Skip
  125: Check Arm CoreSight trace data recording and synthesized samples: Skip
  127: Check Arm SPE trace data recording and synthesized samples      : Skip
  132: Check open filename arg using perf trace + vfs_getname          : FAILED!

After:
  $ perf test trace
   15: Parse sched tracepoints fields                                  : Skip (permissions)
   80: perf ftrace tests                                               : Skip
  105: perf trace enum augmentation tests                              : Skip
  106: perf trace BTF general tests                                    : Skip
  107: perf trace exit race                                            : Skip
  118: probe libc's inet_pton & backtrace it with ping                 : Skip
  125: Check Arm CoreSight trace data recording and synthesized samples: Skip
  127: Check Arm SPE trace data recording and synthesized samples      : Skip
  132: Check open filename arg using perf trace + vfs_getname          : Skip

Tested-by: Thomas Falcon <thomas.falcon@intel.com>
Cc: Howard Chu <howardchu95@gmail.com>
Link: https://lore.kernel.org/r/20250304022837.1877845-4-namhyung@kernel.org


Signed-off-by: Namhyung Kim <namhyung@kernel.org>