Fix bug with function_call_walker(). It always regarded the first element is the function name, which is not true if the function has schema qualification. In this case we should use lsecond() rather than lfirst() to extract the function name because the first element is the schema name.
Fix bug with function_call_walker().
It always regarded the first element is the function name, which is
not true if the function has schema qualification. In this case we
should use lsecond() rather than lfirst() to extract the function name
because the first element is the schema name.

treasure-data/prestogres,treasure-data/prestogres,treasure-data/prestogres,treasure-data/prestogres,treasure-data/prestogres,treasure-data/prestogres,treasure-data/prestogres