Fix Checkstyle violation

See gh-gh-24358

spring-jdbc/src/main/java/org/springframework/jdbc/core/namedparam/NamedParameterJdbcTemplate.java

@@ -430,7 +430,7 @@ public class NamedParameterJdbcTemplate implements NamedParameterJdbcOperations
 			return NamedParameterUtils.parseSqlStatement(sql);
 		}
 		synchronized (this.parsedSqlCache) {
-			return parsedSqlCache.computeIfAbsent(sql, NamedParameterUtils::parseSqlStatement);
+			return this.parsedSqlCache.computeIfAbsent(sql, NamedParameterUtils::parseSqlStatement);
 		}
 	}