State.Power: fix message typo

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I157eb88831ca7513cd708475e88c910b548272f9

Author: williamspatrick

yaml/xyz/openbmc_project/State/Power.events.yaml

@@ -1,4 +1,4 @@
-version: 1.0.0
+version: 1.0.1
 
 errors:
     - name: PowerRailFault
@@ -13,7 +13,7 @@ errors:
             description: An [optional] set of additional failure data.
       en:
           description: A fault has been detected on a power rail.
-          message: A fault has been detected on power rail '{Rail}'.
+          message: A fault has been detected on power rail '{PowerRail}'.
       errno: EIO
 
     - name: VoltageRegulatorFault