6386 Fix function call with uninitialized value in vdev_inuse
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>

*** 594,604 ****
          /*
           * We can't rely on a pool's state if it's been imported
           * read-only.  Instead we look to see if the pools is marked
           * read-only in the namespace and set the state to active.
           */
!         if ((spa = spa_by_guid(pool_guid, device_guid)) != NULL &&
              spa_mode(spa) == FREAD)
                  state = POOL_STATE_ACTIVE;
  
          /*
           * If the device is marked ACTIVE, then this device is in use by another
--- 594,605 ----
          /*
           * We can't rely on a pool's state if it's been imported
           * read-only.  Instead we look to see if the pools is marked
           * read-only in the namespace and set the state to active.
           */
!         if (state != POOL_STATE_SPARE && state != POOL_STATE_L2CACHE &&
!             (spa = spa_by_guid(pool_guid, device_guid)) != NULL &&
              spa_mode(spa) == FREAD)
                  state = POOL_STATE_ACTIVE;
  
          /*
           * If the device is marked ACTIVE, then this device is in use by another