Fix incorrect expected error in ztest

There is an occasional ztest failure that looks like ztest: attach
(/var/tmp/zloop-run/ztest.13a 570425344, draid1-1-0 532152320, 1)
returned 22, expected 95. This is because the value that we return
is EINVAL, but expected_error is set incorrectly.

Change the expected_error value to match both the comment and the
actual error value.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes #15295