[SCSI] qla4xxx: ql4_mbx.c remove dead code bugfixes

All all inbound mbx registers for all mbx commands. Remove dead code.
Signed-off-by: David Somayajulu <david.somayajulu@qlogic.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>