perf script: Fix CPU filtering of a script's switch events

perf script: Fix CPU filtering of a script's switch events

CPU filtering was not being applied to a script's switch events.

Fixes: de590eede64fe07f ("perf script: Add scripting operation process_switch()")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Riccardo Mancini <rickyman7@gmail.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20211215080636.149562-3-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>