[SCSI] qla2xxx: Correctly set fw hung and complete only waiting mbx.

The fw_hung flag should be set ir-respective of if there is a
mbx command pending or not. Also the complete should be called
if there is a mbx waiting.

Signed-off-by: Giridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>