[SCSI] libsas: don't use made up error codes

This is bad for two reasons:

     1. If they're returned to outside applications, no-one knows what
        they mean.
     2. Eventually they'll clash with the ever expanding standard error
        codes.

The problem error code in question is ETASK.  I've replaced this by
ECOMM (communications error on send) a network error code that seems to
most closely relay what ETASK meant.
Acked-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

drivers/scsi/libsas/sas_ata.c

@@ -500,7 +500,7 @@ static int sas_execute_task(struct sas_task *task, void *buffer, int size,
 			goto ex_err;
 		}
 		wait_for_completion(&task->completion);
-		res = -ETASK;
+		res = -ECOMM;
 		if (task->task_state_flags & SAS_TASK_STATE_ABORTED) {
 			int res2;
 			SAS_DPRINTK("task aborted, flags:0x%x\n",

drivers/scsi/libsas/sas_expander.c

@@ -96,7 +96,7 @@ static int smp_execute_task(struct domain_device *dev, void *req, int req_size,
 		}
 
 		wait_for_completion(&task->completion);
-		res = -ETASK;
+		res = -ECOMM;
 		if ((task->task_state_flags & SAS_TASK_STATE_ABORTED)) {
 			SAS_DPRINTK("smp task timed out or aborted\n");
 			i->dft->lldd_abort_task(task);

include/scsi/libsas.h

@@ -91,8 +91,6 @@ enum discover_event {
 
 /* ---------- Expander Devices ---------- */
 
-#define ETASK 0xFA
-
 #define to_dom_device(_obj) container_of(_obj, struct domain_device, dev_obj)
 #define to_dev_attr(_attr)  container_of(_attr, struct domain_dev_attribute,\
                                          attr)