[SCSI] qla4xxx: check for FW alive before calling chip_reset

Check for firmware alive and do premature completion of
mbox commands in case of FW hung before doing chip_reset

Signed-off-by: Shyam Sunder <shyam.sunder@qlogic.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Nilesh Javali <nilesh.javali@qlogic.com>
Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>