* lib/psych.rb (Psych.load): Return value of Psych::SyntaxError.message

  should be same as example. Patch by Ippei Obayashi [ruby-core:51193]

lib/psych.rb

@@ -123,7 +123,7 @@ class BadAlias < Exception
   #     Psych.load("--- `", "file.txt")
   #   rescue Psych::SyntaxError => ex
   #     ex.file    # => 'file.txt'
-  #     ex.message # => "(foo.txt): found character that cannot start any token"
+  #     ex.message # => "(file.txt): found character that cannot start any token"
   #   end
   def self.load yaml, filename = nil
     result = parse(yaml, filename)
@@ -145,7 +145,7 @@ def self.load yaml, filename = nil
   #     Psych.parse("--- `", "file.txt")
   #   rescue Psych::SyntaxError => ex
   #     ex.file    # => 'file.txt'
-  #     ex.message # => "(foo.txt): found character that cannot start any token"
+  #     ex.message # => "(file.txt): found character that cannot start any token"
   #   end
   #
   # See Psych::Nodes for more information about YAML AST.
@@ -195,7 +195,7 @@ def self.parser
   #     Psych.parse_stream("--- `", "file.txt")
   #   rescue Psych::SyntaxError => ex
   #     ex.file    # => 'file.txt'
-  #     ex.message # => "(foo.txt): found character that cannot start any token"
+  #     ex.message # => "(file.txt): found character that cannot start any token"
   #   end
   #
   # See Psych::Nodes for more information about YAML AST.