[SCSI] qla2xxx: Correctly read sfp single byte mailbox register.

When reading a single byte using the READ SFP mailbox command, the
single byte of data is returned in MB[1] and not MB[8].

The reason that MB[8] was being used is that the spec was unclear
as it evolved over time; and we have not needed to read a single
byte until recently.

Signed-off-by: Joe Carnuccio <joe.carnuccio@qlogic.com>
Signed-off-by: Madhuranath Iyengar <Madhu.Iyengar@qlogic.com>
Signed-off-by: James Bottomley <jbottomley@parallels.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>