LU-12904 utils: zfs properly detect spa_multihost

LU-12904 utils: zfs properly detect spa_multihost

spa_multihost is used in a user space tool and the
compile test for spa_multihost reflect that.

Test-Parameters: trivial
Cray-bug-id: LUS-8042
Signed-off-by: Shaun Tancheff <stancheff@cray.com>
Change-Id: Ie85fffb80e84a2b65547e3d48dc0cff31c3325b4
Reviewed-on: https://review.whamcloud.com/36582
Reviewed-by: Nathaniel Clark <nclark@whamcloud.com>
Reviewed-by: Petros Koutoupis <pkoutoupis@cray.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Olaf Faaland-LLNL <faaland1@llnl.gov>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>