BATCH-2411 Remove @SuppressWarnings("unchecked")

The source code contains various @SuppressWarnings("unchecked") that
are no longer unnecessary since the relevant APIs have been upgraded to
support Java 5 generics.

 - remove @SuppressWarnings("unchecked") where no longer unnecessary

Issue: BATCH-2411

spring-batch-samples/src/main/java/org/springframework/batch/sample/quartz/JobLauncherDetails.java

@@ -63,7 +63,6 @@ public class JobLauncherDetails extends QuartzJobBean {
 	}
 
 	@Override
-	@SuppressWarnings("unchecked")
 	protected void executeInternal(JobExecutionContext context) {
 		Map<String, Object> jobDataMap = context.getMergedJobDataMap();
 		String jobName = (String) jobDataMap.get(JOB_NAME);

spring-batch-samples/src/test/java/org/springframework/batch/sample/CompositeItemWriterSampleFunctionalTests.java

@@ -104,7 +104,7 @@ public class CompositeItemWriterSampleFunctionalTests {
 	}
 
 	private void checkOutputFile(String fileName) throws IOException {
-		@SuppressWarnings({ "unchecked", "resource" })
+		@SuppressWarnings("resource")
 		List<String> outputLines = IOUtils.readLines(new FileInputStream(fileName));
 
 		String output = "";