tools/runqslower: Update perf_buffer__new() calls

Use v1.0+ compatible variant of perf_buffer__new() call to prepare for
deprecation.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211111053624.190580-9-andrii@kernel.org