It's not 2&>1, the correct is 2>&1

Fixes: ade1d030 ("perf offcpu: Update offcpu test for child process")
Signed-off-by: Patrice Duroux <patrice.duroux@gmail.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20230303193058.21274-1-patrice.duroux@gmail.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>