Updated threshold arguments due to exceeded character length

Signed-off-by: Marissa Garza <garzam@us.ibm.com>
Change-Id: Iffb94e0732a773b8756c0f0e79295b1ec14c4de3
diff --git a/redfish/systems/test_powersupply_readings.robot b/redfish/systems/test_powersupply_readings.robot
index e7ac350..4c67075 100755
--- a/redfish/systems/test_powersupply_readings.robot
+++ b/redfish/systems/test_powersupply_readings.robot
@@ -85,8 +85,9 @@
 
     ${records}=  Redfish.Get Attribute  ${redfish_uri}  ${record_type}
 
-    ${invalid_records}=  Evaluate
-    ...  [x for x in ${records} if not x['LowerThresholdNonCritical'] <= x['${reading_type}'] <= x['UpperThresholdNonCritical']]
+    ${cmd}  Catenate  [x for x in ${records}
+    ...  if not x['LowerThresholdNonCritical'] <= x['${reading_type}'] <= x['UpperThresholdNonCritical']]
+    ${invalid_records}=  Evaluate  ${cmd}
 
     Valid Length  invalid_records  max_length=0