utils: check to_stdout return correctly in bond2team

to_stdout is a function, not a string, so fix the check on
its return in bond2team.

v1->v2:
  improve the coding style as Flavio suggested.

Fixes: d5a1c8ee9e36 ("utils: add bond2team conversion tool")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Flavio Leitner <fbl@sysclose.org>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
1 file changed