Remove unused method.

Author: viirya

sql/core/src/main/java/org/apache/spark/sql/execution/UnsafeFixedWidthAggregationMap.java

@@ -218,14 +218,6 @@ public void free() {
     map.free();
   }
 
-  @SuppressWarnings("UseOfSystemOutOrSystemErr")
-  public void printPerfMetrics() {
-    System.out.println("Average probes per lookup: " + map.getAverageProbesPerLookup());
-    System.out.println("Number of hash collisions: " + map.getNumHashCollisions());
-    System.out.println("Time spent resizing (ns): " + map.getTimeSpentResizingNs());
-    System.out.println("Total memory consumption (bytes): " + map.getTotalMemoryConsumption());
-  }
-
   /**
    * Gets the average hash map probe per looking up for the underlying `BytesToBytesMap`.
    */