[SCSI] qla4xxx: Fix failure of IDC Time Extend mailbox command

Issue:
Mailbox command 0x102 (IDC Time Extend) failure seen while applying
changes to iface using iscsiadm

Fix:
Added fix to extend IDC timeout only for ISP84xx when IDC ACK
needs to be posted and disable ACB mailbox command completion
is in intermediate state.

Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

drivers/scsi/qla4xxx/ql4_mbx.c

@@ -1922,6 +1922,7 @@ int qla4xxx_disable_acb(struct scsi_qla_host *ha)
 				  mbox_sts[0], mbox_sts[1], mbox_sts[2]));
 	} else {
 		if (is_qla8042(ha) &&
+		    test_bit(DPC_POST_IDC_ACK, &ha->dpc_flags) &&
 		    (mbox_sts[0] != MBOX_STS_COMMAND_COMPLETE)) {
 			/*
 			 * Disable ACB mailbox command takes time to complete