[SCSI] ibmvfc: Fixup GFP flags for target allocations

Since target allocations can occur while resetting the virtual adapter,
we shouldn't be using GFP_KERNEL for them as it could hang. Switch to
use GFP_NOIO.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>