hidpp20: fix Invalid writes
Valgrind complains...
Fixes
@@ -339,7 +339,7 @@ hidpp20_feature_set_get(struct hidpp20_device *device)
if (!feature_count)
return -ENOTSUP;
- flist = zalloc(feature_count * sizeof(struct hidpp20_feature));
+ flist = zalloc((feature_count + 1) * sizeof(struct hidpp20_feature));
/* feature set count does not include the root feature as documented here:
* https://6xq.net/git/lars/lshidpp.git/plain/doc/logitech_hidpp_2.0_specification_draft_2012-06-04.pdf
