Potential bugs in occupancyTableProducer.cxx

[vkucera]

Dear @rahulverma012 , Cppcheck has found the following issues in Common/TableProducer/occupancyTableProducer.cxx. Most of them look like bugs or ineffective statements.
Can you please check and fix them?

Common/TableProducer/occupancyTableProducer.cxx:480:142: warning: Identical condition 'meanRobustTableMode==checkTableMode', second condition is always false [identicalConditionAfterEarlyExit]
Common/TableProducer/occupancyTableProducer.cxx:1806:102: warning: Identical condition 'qaMode==checkQAMode', second condition is always false [identicalConditionAfterEarlyExit]
Common/TableProducer/occupancyTableProducer.cxx:1961:34: warning: Identical condition 'doAmbgUpdate', second condition is always false [identicalConditionAfterEarlyExit]
Common/TableProducer/occupancyTableProducer.cxx:1966:15: warning: Identical condition 'doAmbgUpdate', second condition is always false [identicalConditionAfterEarlyExit]
Common/TableProducer/occupancyTableProducer.cxx:443:29: style: The if condition is the same as the previous if condition [duplicateCondition]
Common/TableProducer/occupancyTableProducer.cxx:454:33: style: The if condition is the same as the previous if condition [duplicateCondition]
Common/TableProducer/occupancyTableProducer.cxx:465:35: style: The if condition is the same as the previous if condition [duplicateCondition]
Common/TableProducer/occupancyTableProducer.cxx:476:39: style: The if condition is the same as the previous if condition [duplicateCondition]
Common/TableProducer/occupancyTableProducer.cxx:1772:33: style: The if condition is the same as the previous if condition [duplicateCondition]
Common/TableProducer/occupancyTableProducer.cxx:1783:39: style: The if condition is the same as the previous if condition [duplicateCondition]
Common/TableProducer/occupancyTableProducer.cxx:805:61: style: Same expression on both sides of '/'. [duplicateExpression]
Common/TableProducer/occupancyTableProducer.cxx:2424:5: style: Statements following 'return' will never be executed. [unreachableCode]