Avoid repeated value read in SubtractionAnimatedNode

Summary:
Minor optimization, but spotted this while reviewing the implementation for D33622997

Changelog: [Internal]

Reviewed By: mdvacca

Differential Revision: D33622996

fbshipit-source-id: 8712753803fc46e6a046d50f77454a813e4a641a

ReactAndroid/src/main/java/com/facebook/react/animated/SubtractionAnimatedNode.java

@@ -38,12 +38,12 @@ import com.facebook.react.bridge.ReadableMap;
         double value = ((ValueAnimatedNode) animatedNode).getValue();
         if (i == 0) {
           mValue = value;
-          continue;
+        } else {
+          mValue -= value;
         }
-        mValue -= ((ValueAnimatedNode) animatedNode).getValue();
       } else {
         throw new JSApplicationCausedNativeException(
-            "Illegal node ID set as an input for " + "Animated.subtract node");
+            "Illegal node ID set as an input for Animated.subtract node");
       }
     }
   }