scsi: zfcp: Move p-t-p port allocation to after xport data

scsi: zfcp: Move p-t-p port allocation to after xport data

When doing the very first adapter recovery - initialization - for a FCP
device in a point-to-point topology we also allocate the port object
corresponding to the attached remote port, and trigger a port recovery for
it that will run after the adapter recovery finished.

Right now this happens right after we finished with the exchange config
data command, and uses the fibre channel host object corresponding to the
FCP device to determine whether a point-to-point topology is used.

When moving the scsi host object allocation and registration - and thus
also the fibre channel host object allocation - to after the first exchange
config and exchange port data, this use of the fc_host object is not
possible anymore at that point in the work flow.

But the allocation and recovery trigger doesn't have notable side-effects
on the following exchange port data processing, so we can move those to
after xport data, and thus also to after the scsi host object allocation,
once we move it. Then the fc_host object can be used again, like it is now.

For any further adapter recoveries this doesn't change anything, because at
that point the port object already exists and recovery is triggered
elsewhere for existing port objects.

Link: https://lore.kernel.org/r/73e5d4ac21e2b37bf0c3ca8e530bc5a5c6e74f8f.1588956679.git.bblock@linux.ibm.com
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>