Fixed sonar blocker issue in VolumeReport.java
fixed 3 blocker issues.
"https://sonar.onap.org/project/issues?fileUuids=AWHFaQitEU5FCDfKtnER
&id=org.onap.dmaap.datarouter%3Aparent&open=AWHFaQlfEU5FCDfKtnIp&resolved=false&severities=BLOCKER"
"https://sonar.onap.org/project/issues?fileUuids=AWHFaQitEU5FCDfKtnER
&id=org.onap.dmaap.datarouter%3Aparent&open=AWHFaQlfEU5FCDfKtnIo&resolved=false&severities=BLOCKER"
"https://sonar.onap.org/project/issues?fileUuids=AWHFaQitEU5FCDfKtnER
&id=org.onap.dmaap.datarouter%3Aparent&open=AWHFaQlfEU5FCDfKtnIq&resolved=false&severities=BLOCKER"
Issue-ID: DMAAP-675
Change-Id: I1eba5aa926dba7c83e6180c544854879b835bf94
Signed-off-by: Amaresh Kumar <kamaresh@in.ibm.com>