[SCSI] qla2xxx: Correction to sysfs edc interface.

Corrects the return value for the cases where read/write edc fails;
this prevents sysfs from retrying the operation until forever.

Corrects the printk width specifier for the first byte of buf.

Signed-off-by: Joe Carnuccio <joe.carnuccio@qlogic.com>
Signed-off-by: Chad Dupuis <chad.dupuis@qlogic.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>