Fix typo in `Timeout` doc [ci skip]

Author: yuuji.yaginuma <yuuji.yaginuma@gmail.com>
https://github.com/ruby/ruby/pull/1760
[Fix GH-1760]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60827 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/timeout.rb

@@ -15,7 +15,7 @@
 #
 # Previous versions didn't use a module for namespacing, however
 # #timeout is provided for backwards compatibility.  You
-# should prefer Timeout#timeout instead.
+# should prefer Timeout.timeout instead.
 #
 # == Copyright
 #
@@ -23,7 +23,7 @@
 # Copyright:: (C) 2000  Information-technology Promotion Agency, Japan
 
 module Timeout
-  # Raised by Timeout#timeout when the block times out.
+  # Raised by Timeout.timeout when the block times out.
   class Error < RuntimeError
     attr_reader :thread