XXX Remove nawk(1)

*** 75,88 ****
  {
          typeset options=$1
          typeset file_size=$2
          typeset refer_diff=$($ECHO "$refer_size - $estimate_size" | bc)
          refer_diff=$($ECHO "$refer_diff / 1" | bc)
!         refer_diff=$($ECHO "$refer_diff" | $NAWK '{print ($1 < 0) ? ($1 * -1): $1'})
          typeset file_diff=$($ECHO "$file_size - $estimate_size" | bc)
          file_diff=$($ECHO "$file_diff / 1" | bc)
!         file_diff=$($ECHO "$file_diff" | $NAWK '{print ($1 < 0) ? ($1 * -1):$1'})
          typeset expected_diff=$(cal_percentage $refer_size)
  
          [[ -z $refer_diff && -z $file_diff && -z $expected_diff ]] && \
              log_fail "zfs send $options failed"
          [[ $refer_diff -le $expected_diff &&  \
--- 75,88 ----
  {
          typeset options=$1
          typeset file_size=$2
          typeset refer_diff=$($ECHO "$refer_size - $estimate_size" | bc)
          refer_diff=$($ECHO "$refer_diff / 1" | bc)
!         refer_diff=$($ECHO "$refer_diff" | $AWK '{print ($1 < 0) ? ($1 * -1): $1'})
          typeset file_diff=$($ECHO "$file_size - $estimate_size" | bc)
          file_diff=$($ECHO "$file_diff / 1" | bc)
!         file_diff=$($ECHO "$file_diff" | $AWK '{print ($1 < 0) ? ($1 * -1):$1'})
          typeset expected_diff=$(cal_percentage $refer_size)
  
          [[ -z $refer_diff && -z $file_diff && -z $expected_diff ]] && \
              log_fail "zfs send $options failed"
          [[ $refer_diff -le $expected_diff &&  \