Drop redundant NULL assignments after MemSet

graph_name and params are already zeroed by the MemSet, so the explicit
NULL assignments are not needed.

Author: claude

src/backend/parser/cypher_analyze.c

@@ -963,8 +963,6 @@ static Query *analyze_cypher(List *stmt, ParseState *parent_pstate,
      */
     MemSet(&parent_cpstate, 0, sizeof(parent_cpstate));
     parent_cpstate.pstate = *parent_pstate;
-    parent_cpstate.graph_name = NULL;
-    parent_cpstate.params = NULL;
 
     cpstate = make_cypher_parsestate(&parent_cpstate);