kmem_scnprintf() is only available in libzpool. Recent buildbot issues
with showing FreeBSD results kept us from seeing this before
97143b9d31 was merged.
The code has been changed to sanitize the output from `kmem_scnprintf()`.
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14111