subparse: don't deref a potentially NULL variable
If the html SAMI data is malformed, then retrieving the attribute name may fail. We then cannot retrieve the attribute value.
Fixes: https://oss-fuzz.com/testcase-detail/4700130671984640
If the html SAMI data is malformed, then retrieving the attribute name may fail. We then cannot retrieve the attribute value.
Fixes: https://oss-fuzz.com/testcase-detail/4700130671984640