perf test: Update ftrace test to use --graph-opts

I found it failed on machines with limited memory because 16M byte
per-cpu buffer is too big.  The reason it added the option is not to
miss tracing data.  Thus we can limit the data size by reducing the
function call depth instead of increasing the buffer size to handle the
whole data.

As it used the same option in the test_ftrace_trace() and it was able
to find the sleep function, it should work with the profile subcommand.

Get rid of other grep commands which might be affected by the depth
change.

Reported-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Link: https://lore.kernel.org/r/20250107224352.1128669-3-namhyung@kernel.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>