Fix Javadoc typos (#3010)

Author: TheJavaGuy

log4j-core/src/main/java/org/apache/logging/log4j/core/util/datetime/FastDatePrinter.java

@@ -457,7 +457,7 @@ private String applyRulesToString(final Calendar c) {
     }
 
     /**
-     * Creation method for new calender instances.
+     * Creation method for new calendar instances.
      * @return a new Calendar instance.
      */
     private Calendar newCalendar() {

log4j-jul/src/test/java/org/apache/logging/log4j/jul/test/Log4jBridgeHandlerTest.java

@@ -393,7 +393,7 @@ private static void debugPrintJulLoggers(final String infoStr) {
 
     ////////////////
     ////////////////   INTERNAL DEVELOPER TESTS follow
-    ////////////////   (these are NOT neccessary for unit test but source is kept here for reference and info)
+    ////////////////   (these are NOT necessary for unit test but source is kept here for reference and info)
 
     static {
         if (DEVTEST) {