perf ftrace: Remove an unnecessary condition check in BPF

The bucket_num is set based on the {max,min}_latency already in
cmd_ftrace(), so no need to check it again in BPF.  Also I found
that it didn't pass the max_latency to BPF. :)

No functional changes intended.

Cc: Gabriele Monaco <gmonaco@redhat.com>
Link: https://lore.kernel.org/r/20250227191223.1288473-2-namhyung@kernel.org


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