[SCSI] qla2xxx: Do not enable VP in non fabric topology.

After topology change ISP is reset and VPs are re-enabled.
If the topology is not fabric, VPs could falsely get enabled.

Signed-off-by: Giridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>