zpool list, which is the only user, would mistakenly try to parse the
empty string as the interval in this case:
$ zpool list "a"
cannot open 'a': no such pool
$ zpool list ""
interval cannot be zero
usage: <usage string follows>
which is now symmetric with zpool get:
$ zpool list ""
cannot open '': name must begin with a letter
Avoid breaking the "interval cannot be zero" string.
There simply isn't a need for this, and it's user-facing.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#11841Closes#11843