signlk: do not clean tmpdir in debug mode

Signed-off-by: Nicolas Dechesne <nicolas.dechesne@linaro.org>

signlk.sh

@@ -176,6 +176,8 @@ dd if=$ROOT of=$OUTFILE count=$root_file_size bs=1 seek=$[$hash_seg_offset+$mi_h
 dd if=$tmpdir/hashSeg of=$OUTFILE bs=1 skip=$[$mi_hdr_size+$data_file_size+$sig_file_size+$atte_file_size+$root_file_size] seek=$[$hash_seg_offset+$mi_hdr_size+$data_file_size+$sig_file_size+$atte_file_size+$root_file_size] 2>/dev/null
 dd if=$TMPOUTFILE of=$OUTFILE bs=1 skip=$[$hash_seg_offset+$hash_seg_file_size] seek=$[$hash_seg_offset+$hash_seg_file_size] 2>/dev/null
 
-rm -rf $tmpdir
+if ! [[ $- =~ x ]]; then
+  rm -rf $tmpdir
+fi
 
 echo done