Change two MallocZero() calls into MallocRaw() to avoid unnecessary memset().

FossilOrigin-Name: ff5e733cbffd73faa4046e0f1c7f24bb6e131738
diff --git a/src/expr.c b/src/expr.c
index 505e56a..2bf76eb 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -2367,7 +2367,7 @@
   char *zRet;
 
   assert( pExpr->op==TK_IN );
-  zRet = sqlite3DbMallocZero(pParse->db, nVal+1);
+  zRet = sqlite3DbMallocRaw(pParse->db, nVal+1);
   if( zRet ){
     int i;
     for(i=0; i<nVal; i++){