Fix zpool subcommands error message with some unsupported options
Both 'detach' and 'online' zpool subcommands, when provided with an
unsupported option, forget to print it in the error message:
- zpool online -t rpool vda3 invalid option '' usage: online [-e] <pool> <device> ...
This changes fixes the error message in order to include the actual
option that is not supported.
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
Closes #9270