MINOR: Fix a few typos in clients and core tests (apache#15725)

Reviewers: Mickael Maison <[email protected]>, Luke Chen <[email protected]>, Igor Soarez<[email protected]>
Co-authored-by: lixinyang <[email protected]>

clients/src/test/java/org/apache/kafka/common/requests/BrokerRegistrationRequestTest.java

@@ -63,10 +63,10 @@ public void testBasicBuild(short version) {
         buf.flip();
         data2.read(byteBufferAccessor, version);
 
-        assertEquals(0, data2.brokerId(), "Unepxected broker ID in " + data2);
+        assertEquals(0, data2.brokerId(), "Unexpected broker ID in " + data2);
         assertEquals("test", data2.clusterId(), "Unexpected cluster ID in " + data2);
-        assertEquals(incarnationId, data2.incarnationId(), "Unepxected incarnation ID in " + data2);
-        assertEquals("a", data2.rack(), "Unepxected rack in " + data2);
+        assertEquals(incarnationId, data2.incarnationId(), "Unexpected incarnation ID in " + data2);
+        assertEquals("a", data2.rack(), "Unexpected rack in " + data2);
         if (version >= 3) {
             assertEquals(1, data2.previousBrokerEpoch(), "Unexpected previousBrokerEpoch in " + data2);
         } else {

core/src/test/scala/unit/kafka/server/AbstractFetcherThreadTest.scala

@@ -692,7 +692,7 @@ class AbstractFetcherThreadTest {
     fetcher.doWork()
     if (truncateOnFetch) {
       // Second iteration required here since first iteration is required to
-      // perform initial truncaton based on diverging epoch.
+      // perform initial truncation based on diverging epoch.
       fetcher.doWork()
     }
     assertEquals(Option(Fetching), fetcher.fetchState(partition).map(_.state))