Polish JobLauncherCommandLineRunner

The JobLauncherCommandLineRunner reassigned method arguments inside the
merge method. Instead of reassigning the method argument just return
the new instance directly.

Also some minor cleanup (unnesseccary null check and continue keyword).

Closes gh-10612

Author: mdeinum

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

@@ -181,8 +181,7 @@ private JobParameters merge(JobParameters parameters,
 		Map<String, JobParameter> merged = new HashMap<String, JobParameter>();
 		merged.putAll(parameters.getParameters());
 		merged.putAll(additionals);
-		parameters = new JobParameters(merged);
-		return parameters;
+		return new JobParameters(merged);
 	}
 
 	private void executeRegisteredJobs(JobParameters jobParameters)
@@ -199,7 +198,6 @@ private void executeRegisteredJobs(JobParameters jobParameters)
 				}
 				catch (NoSuchJobException ex) {
 					logger.debug("No job found in registry for job name: " + jobName);
-					continue;
 				}
 			}
 		}
@@ -210,11 +208,9 @@ protected void execute(Job job, JobParameters jobParameters)
 			JobInstanceAlreadyCompleteException, JobParametersInvalidException,
 			JobParametersNotFoundException {
 		JobParameters nextParameters = getNextJobParameters(job, jobParameters);
-		if (nextParameters != null) {
-			JobExecution execution = this.jobLauncher.run(job, nextParameters);
-			if (this.publisher != null) {
-				this.publisher.publishEvent(new JobExecutionEvent(execution));
-			}
+		JobExecution execution = this.jobLauncher.run(job, nextParameters);
+		if (this.publisher != null) {
+			this.publisher.publishEvent(new JobExecutionEvent(execution));
 		}
 	}