Use @return $this where applicable (#1828)

src/Monolog/ErrorHandler.php

@@ -63,7 +63,7 @@ class ErrorHandler
      * @param  array<int, LogLevel::*>|false          $errorLevelMap     an array of E_* constant to LogLevel::* constant mapping, or false to disable error handling
      * @param  array<class-string, LogLevel::*>|false $exceptionLevelMap an array of class name to LogLevel::* constant mapping, or false to disable exception handling
      * @param  LogLevel::*|null|false                 $fatalLevel        a LogLevel::* constant, null to use the default LogLevel::ALERT or false to disable fatal error handling
-     * @return ErrorHandler
+     * @return static
      */
     public static function register(LoggerInterface $logger, $errorLevelMap = [], $exceptionLevelMap = [], $fatalLevel = null): self
     {
@@ -126,6 +126,7 @@ class ErrorHandler
     /**
      * @param LogLevel::*|null $level              a LogLevel::* constant, null to use the default LogLevel::ALERT
      * @param int              $reservedMemorySize Amount of KBs to reserve in memory so that it can be freed when handling fatal errors giving Monolog some room in memory to get its job done
+     * @return $this
      */
     public function registerFatalHandler($level = null, int $reservedMemorySize = 20): self
     {