perf test: perf header test fails on s390

perf test: perf header test fails on s390

commit 2d584688643fa ("perf test: Add header shell test")
introduced a new test case for perf header. It fails on s390
because call graph option -g is not supported on s390.
Also the option --call-graph dwarf is only supported for
the event cpu-clock.

Remove this option and the test succeeds.

Output after:
 # ./perf test 76
 76: perf header tests                           : Ok

Fixes: 2d584688643fa ("perf test: Add header shell test")
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Link: https://lore.kernel.org/r/20250630091613.3061664-1-tmricht@linux.ibm.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>