Remove unnecessary local variable

Bug: 271500140
Test: Enavble AIDL
Test: atest EffectProxyTest
Change-Id: I6849e9631a520cc30247063479ba1b5d358d7d4b
diff --git a/media/libaudiohal/impl/EffectProxy.cpp b/media/libaudiohal/impl/EffectProxy.cpp
index fc2da6b..5e465d9 100644
--- a/media/libaudiohal/impl/EffectProxy.cpp
+++ b/media/libaudiohal/impl/EffectProxy.cpp
@@ -92,9 +92,7 @@
                                                                 "noActiveEffctFound");
     }
 
-    const size_t newIndex = std::distance(mSubEffects.begin(), itor);
-    mActiveSubIdx = newIndex;
-
+    mActiveSubIdx = std::distance(mSubEffects.begin(), itor);
     ALOGI("%s: active %soffload sub-effect %zu descriptor: %s", __func__,
           offload->isOffload ? "" : "non-", mActiveSubIdx,
           ::android::audio::utils::toString(mSubEffects[mActiveSubIdx].descriptor.common.id.uuid)