[SCSI] qla4xxx: do not retry login to CHAP auth failed targets

Per RFC 3720, Login Response Status Code 0x02 should not be retried.
Condensed connection error checking code to a single routine, and
added check for status class 0x02.

Signed-off-by: Karen Higgins <karen.higgins@qlogic.com>
Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: Ravi Anand <ravi.anand@qlogic.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>