onerng verification only needs to be confirmed once

src/freedombone

 }
 
 function check_onerng_verification {
+  if grep -Fxq "check_onerng_verification" $COMPLETION_FILE; then
+      return
+  fi
   if [[ $HWRNG_TYPE != "onerng" ]]; then
       return
   fi
   echo 'OneRNG firmware verification passed'
   # if haveged was previously installed then remove it
   apt-get -y remove haveged
+  echo 'check_onerng_verification' >> $COMPLETION_FILE
 }
 
 function install_onerng {