Clean up temporary data created by test

tests/bufrdc_ref.sh

@@ -27,12 +27,13 @@ do
   ref_num=$file.num.ref
   diff_num=$file.num.diff
 
-  rm -f $res_num | true
+  rm -f $res_num
 
   ${tools_dir}/codes_bufr_filter bufrdc_num_ref.filter $file 2> $REDIRECT > $res_num
 
   # Exclude the BUFR file uegabe.bufr because its reference file is incorrect
   if [ "$bf" = "uegabe.bufr" ]; then
+    rm -f $res_num
     continue
   fi
 
@@ -42,6 +43,7 @@ do
     #numdiff               $ref_num $res_num >$REDIRECT 2> $REDIRECT
   fi
 
+  rm -f $res_num
 done
 
 rm -f bufrdc_num_ref.filter