fix formatting issues

Author: lennart

src/main/java/com/thealgorithms/tree/CentroidDecomposition.java

@@ -129,7 +129,6 @@ public void findSubtreeSizes(int src) {
     }
 
     public void findCentroid(int src, int previousCentroid) {
-        
         Arrays.fill(visited, false);
         findSubtreeSizes(src);
         int treeSize = subtreeSizes[src];

src/test/java/com/thealgorithms/tree/CentroidDecompositionTest.java

@@ -58,7 +58,6 @@ void setUp() {
          4     5 2 12 14   3  9 10
                 / \    / \
                7   6  15 13
-   
          */
     }