[SCSI] qla2xxx: Correct issue where driver improperly issued SNS commands in N2N topologies.

Semantic changes in ISP24xx firmware behaviour inadvertently
caused the driver to believe an F-port topology was present in an
N_port-to-N_port configuration.

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