[SCSI] qla2xxx: Cleanup FC remote port registration.

Cleanup FC remote port registration.

Due to the inherent behaviour (an immediate scan) of adding
a 'target'-role-capable rport via fc_remote_port_add(),
split the registration into two steps -- addition as
unknown-type role, then use fc_remote_port_rolchg() with
appropriate role (based on PLOGI/PRLI bits).  This allows
for a more cleaner rport->dd_data management as can be seen
with the simplified qla2xxx_slave_alloc() function.

Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>