zfcp: fix fc_host port_type with NPIV

zfcp: fix fc_host port_type with NPIV

For an NPIV-enabled FCP device, zfcp can erroneously show
"NPort (fabric via point-to-point)" instead of "NPIV VPORT"
for the port_type sysfs attribute of the corresponding
fc_host.
s390-tools that can be affected are dbginfo.sh and ziomon.

zfcp_fsf_exchange_config_evaluate() ignores
fsf_qtcb_bottom_config.connection_features indicating NPIV
and only sets fc_host_port_type to FC_PORTTYPE_NPORT if
fsf_qtcb_bottom_config.fc_topology is FSF_TOPO_FABRIC.

Only the independent zfcp_fsf_exchange_port_evaluate()
evaluates connection_features to overwrite fc_host_port_type
to FC_PORTTYPE_NPIV in case of NPIV.
Code was introduced with upstream kernel 2.6.30
commit b711a20700b52ccd622d11da73ee384b42535e62
("[SCSI] zfcp: Report fc_host_port_type as NPIV").

This works during FCP device recovery (such as set online)
because it performs FSF_QTCB_EXCHANGE_CONFIG_DATA followed by
FSF_QTCB_EXCHANGE_PORT_DATA in sequence.

However, the zfcp-specific scsi host sysfs attributes
"requests", "megabytes", or "seconds_active" trigger only
zfcp_fsf_exchange_config_evaluate() resetting fc_host
port_type to FC_PORTTYPE_NPORT despite NPIV.

The zfcp-specific scsi host sysfs attribute "utilization"
triggers only zfcp_fsf_exchange_port_evaluate() correcting
the fc_host port_type again in case of NPIV.

Evaluate fsf_qtcb_bottom_config.connection_features
in zfcp_fsf_exchange_config_evaluate() where it belongs to.

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: b711a20700b5 ("[SCSI] zfcp: Report fc_host_port_type as NPIV")
Cc: <stable@vger.kernel.org> #2.6.30+
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>