[SCSI] bfa: fix system crash when reading sysfs fc_host statistics

The port data structure related to fc_host statistics collection is
not initialized. This causes system crash when reading the fc_host
statistics. The fix is to initialize port structure during driver
attach.

Signed-off-by: Krishna Gudipati <kgudipat@brocade.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>