[SCSI] lpfc: Fix for "command completion for iotax x?? not found"

From: James Smart <James.Smart@emulex.com>

There were scenarios where the error handlers could reuse an iotag
value of an active io.  Remove all possibility of this by
pre-assigning iotag resources to command resources.

Signed-off-by: James Smart <James.Smart@emulex.com>

Rejections fixed up and
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>