ipr: Fix sync scsi scan

Commit b195d5e2

 ("ipr: Wait to do async scan until scsi host is
initialized") fixed async scan for ipr, but broke sync scan. This fixes
sync scan back up.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>