perf bench numa: Remove dead code in parse_nodes_opt()

perf bench numa: Remove dead code in parse_nodes_opt()

In the function parse_nodes_opt(), the statement "return 0;" is dead
code, remove it.

Signed-off-by: Peng Fan <fanpeng@loongson.cn>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/1597401894-27549-1-git-send-email-fanpeng@loongson.cn
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>