Fix invalid parameter in energy scale test

On Redfish, energy scale parameter needs to be integer not string.

Change-Id: I03e8ca8d5f737fabfce0ca3cd9b96925e1d397ae
Signed-off-by: Steven Sombar <ssombar@us.ibm.com>
diff --git a/tests/test_escale_base.robot b/tests/test_escale_base.robot
index a4c2d40..ed5b01c 100755
--- a/tests/test_escale_base.robot
+++ b/tests/test_escale_base.robot
@@ -125,7 +125,8 @@
     Set DCMI Power Limit And Verify  ${good_power}
 
     # Attempt set power limit out of range.
-    ${data}=  Create Dictionary  data=${outside_bounds_power}
+    ${int_power_limit}=  Convert To Integer  ${outside_bounds_power}
+    ${data}=  Create Dictionary  data=${int_power_limit}
     Write Attribute   ${CONTROL_HOST_URI}power_cap  PowerCap  data=${data}