title: awk gensub function usage issue
body: <pre><code>cat file
  
  ^QciProfilePredefined=qci2$ logicalChannelGroupRef QciTable=default,LogicalChannelGroup=2
  EUtranCellTDD=.*-1[123456],UeMeasControl=1,ReportConfigA4=1$ a4ThresholdRsrp -140
  </code></pre>
  
  <p>I want to use gensub() to delete the content before the last comma in $1(also delete the comma),without make influence other column which contains comma.</p>
  
  <p>my code:</p>
  
  <pre><code>awk '{$1=gensub(/.*,/,"",1);print}' file
  </code></pre>
  
  <p>output:</p>
  
  <pre><code>LogicalChannelGroup=2 logicalChannelGroupRef QciTable=default,LogicalChannelGroup=2
  ReportConfigA4=1$ a4ThresholdRsrp -140 a4ThresholdRsrp -140
  </code></pre>
  
  <p>It seems that the ROW 2 content repeated by "4ThresholdRsrp -140".</p>
  
  <p>The output I expected:</p>
  
  <pre><code>LogicalChannelGroup=2 logicalChannelGroupRef QciTable=default,LogicalChannelGroup=2
  ReportConfigA4=1$ a4ThresholdRsrp -140
  </code></pre>