You need to amend a little bit your command line in order to include some more properties responsible for the results file configuration like:
jmeter -Jjmeter.save.saveservice.output_format=xml -Jjmeter.save.saveservice.response_data=true -Jjmeter.save.saveservice.samplerData=true -Jjmeter.save.saveservice.requestHeaders=true -J jmeter.save.saveservice.responseHeaders=true -Jjmeter.save.saveservice.url=true n -t nmame.jmx -l JmeterReports/TestReport.jtl
In order to make the change permanent add the next lines to user.properties file (lives in "bin" folder of your JMeter installation)
jmeter.save.saveservice.output_format=xml
jmeter.save.saveservice.response_data=true
jmeter.save.saveservice.samplerData=true
jmeter.save.saveservice.requestHeaders=true
jmeter.save.saveservice.responseHeaders=true
jmeter.save.saveservice.url=true
More information: How to Save Response Data in JMeter