Fix status command options in zpool(8)

The 'zpool status' command supports the -P option for printing full
path names. It does not support the -p parsable option for printing
exact values.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #6792
Closes #6794