Fix incorrect documentation for keyword args

Changes:
Fix incorrect documentation for keyword arguments

Tested:
NA

Change-Id: Icb12076b16331651e9079806d899502501509875
Signed-off-by: Sridevi Ramesh <sridevra@in.ibm.com>
diff --git a/redfish/systems/test_alternate_fan_settings.robot b/redfish/systems/test_alternate_fan_settings.robot
index 6157350..b88c330 100755
--- a/redfish/systems/test_alternate_fan_settings.robot
+++ b/redfish/systems/test_alternate_fan_settings.robot
@@ -123,6 +123,10 @@
     [Documentation]  Verify the thermal mode remains set at runtime.
     [Arguments]  ${pre_req_state}  ${thermal_mode}
 
+    # Description of Arguments(s):
+    # pre_req_state      Set the state of the host to Standby or Runtime (e.g. "Running")
+    # thermal_mode       Read the supported thermal mode (e.g. "CUSTOM")
+
     Set and Verify Thermal Mode Switches  ${pre_req_state}  ${thermal_mode}
 
     Run Key U  Redfish Power On \ stack_mode=normal \ quiet=1