perf record: Handle argument change in sched_switch

Recently sched_switch tracepoint added a new argument for prev_state,
but it's hard to handle the change in a BPF program.  Instead, we can
check the function prototype in BTF before loading the program.

Thus I make two copies of the tracepoint handler and select one based
on the BTF info.

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