Merge pull request ARMmbed#80 from linlingao/fix_scan

Fix scan when the count is non-zero

targets/TARGET_TI/TARGET_CC32XX/TARGET_CC3220SF/device/cc3200_simplelink.cpp

@@ -371,10 +371,6 @@ int CC3200_SIMPLELINK::scan(WiFiAccessPoint *res, unsigned count)
      * The scan parameters would be according to the system persistent settings on enabled channels.
      * For more information, see: <simplelink user guide, page: pr.>
      */
-    if (ret > 0)
-    {
-        return ret;
-    }
 
     if(SL_ERROR_WLAN_GET_NETWORK_LIST_EAGAIN == ret)
     {
@@ -410,12 +406,13 @@ int CC3200_SIMPLELINK::scan(WiFiAccessPoint *res, unsigned count)
             }
         }
     }
-    if (triggeredScanTrials == MAX_SCAN_ATTEMPTS)
+    if (ret <= 0)
     {
         printf("\n\r[scan] : Unable to retrieve the network list\n\r");
         return 0;
     }
-    if ((ret > 0) && res)
+    // scan is successful if code reaches here.
+    if (res && count)
     {
         unsigned i;
 
@@ -451,8 +448,12 @@ int CC3200_SIMPLELINK::scan(WiFiAccessPoint *res, unsigned count)
             ap.channel = netEntries[i].Channel;
             res[i] = WiFiAccessPoint(ap);
         }
+        return count;
+    }
+    else // Either res == NULL or count == 0, return the number of scanned networks
+    {
+        return ret;
     }
-    return count;
 }
 
 nsapi_error_t CC3200_SIMPLELINK::set_channel(int channel)