Remove unused interpolate

Interpolate was used prior to the ngToast.
https://github.com/openbmc/phosphor-webui/commit/92d13b62f56fa302a8231690e7371c6ae04f50ba#diff-bbc57e73eb8aa4f1c2de7b8e033393e3
moved to ngToast and removed the use of interpolate.

Tested: Build this and the commits below and loaded onto a Witherspoon
system. Did a power on, warm reboot, and immediate shutdown.
Change-Id: I99c2f3705df413fc744066dd34ba38a383c174fc
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>
diff --git a/app/server-control/controllers/power-operations-controller.js b/app/server-control/controllers/power-operations-controller.js
index 0993d72..2030b4d 100644
--- a/app/server-control/controllers/power-operations-controller.js
+++ b/app/server-control/controllers/power-operations-controller.js
@@ -11,10 +11,10 @@
 
   angular.module('app.serverControl').controller('powerOperationsController', [
     '$scope', 'APIUtils', 'dataService', 'Constants', '$timeout', '$interval',
-    '$interpolate', '$q', 'toastService',
+    '$q', 'toastService',
     function(
-        $scope, APIUtils, dataService, Constants, $timeout, $interval,
-        $interpolate, $q, toastService) {
+        $scope, APIUtils, dataService, Constants, $timeout, $interval, $q,
+        toastService) {
       $scope.dataService = dataService;
       // Is a || of the other 4 "confirm" variables to ensure only
       // one confirm is shown at a time.