[SCSI] qla4xxx: Do not send mbox command if FW is in failed state

FW is not able to process mbox command if FW state is failed. This will cause
mbox command to timeout and adapter reset. We have separate function to detect
FW failed state and do adapter reset. So to avoid mbox command timeout, do not
process mbox command in case of FW state failed.

Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: Prasanna Mumbai <prasanna.mumbai@qlogic.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>