argh! we don't want to NULL the stmt here; freeing the results is not the same

as destroying the prepared statement handler, so we're leaking and breaking, as
can be seen by running the test suite.

brown paper bag for PDO in PHP 5.1RC4?

ext/pdo_mysql/mysql_statement.c

@@ -244,7 +244,6 @@ static int pdo_mysql_stmt_next_rowset(pdo_stmt_t *stmt TSRMLS_DC)
 #if HAVE_MYSQL_STMT_PREPARE
 	if (S->stmt) {
 		mysql_stmt_free_result(S->stmt);
-		S->stmt = NULL;
 	}
 #endif
 	if (S->result) {
@@ -574,7 +573,6 @@ static int pdo_mysql_stmt_cursor_closer(pdo_stmt_t *stmt TSRMLS_DC)
 #if HAVE_MYSQL_STMT_PREPARE
 	if (S->stmt) {
 		int retval = mysql_stmt_free_result(S->stmt);
-		S->stmt = NULL;
 		return retval ? 0 : 1;
 	}
 #endif