Remove compiler warnings related to Batch upgrade

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/batch/BatchAutoConfiguration.java

@@ -101,7 +101,7 @@ public class BatchAutoConfiguration {
 		JobExplorerFactoryBean factory = new JobExplorerFactoryBean();
 		factory.setDataSource(dataSource);
 		factory.afterPropertiesSet();
-		return (JobExplorer) factory.getObject();
+		return factory.getObject();
 	}
 
 	@Bean

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/batch/BatchAutoConfigurationTests.java

@@ -253,7 +253,7 @@ public class BatchAutoConfigurationTests {
 			MapJobExplorerFactoryBean explorer = new MapJobExplorerFactoryBean(
 					this.factory);
 			explorer.afterPropertiesSet();
-			return (JobExplorer) explorer.getObject();
+			return explorer.getObject();
 		}
 	}
 

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/batch/JobLauncherCommandLineRunnerTests.java

@@ -179,8 +179,7 @@ public class JobLauncherCommandLineRunnerTests {
 
 		@Bean
 		public JobExplorer jobExplorer() throws Exception {
-			return (JobExplorer) new MapJobExplorerFactoryBean(this.jobRepositoryFactory)
-					.getObject();
+			return new MapJobExplorerFactoryBean(this.jobRepositoryFactory).getObject();
 		}
 	}