* thread.c: Mutex#owned? is no longer experimental since 2.1.0

[fix GH-839][ci skip] Patch by @takiy33

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@49878 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Sat Mar  7 09:28:02 2015  SHIBATA Hiroshi  <shibata.hiroshi@gmail.com>
+
+	* thread.c: Mutex#owned? is no longer experimental since 2.1.0
+	  [fix GH-839][ci skip] Patch by @takiy33
+
 Sat Mar  7 09:18:42 2015  SHIBATA Hiroshi  <shibata.hiroshi@gmail.com>
 
 	* tool/merger.rb: Added documentation to version method.

thread.c

@@ -4356,7 +4356,6 @@ rb_mutex_lock(VALUE self)
  *    mutex.owned?  -> true or false
  *
  * Returns +true+ if this lock is currently held by current thread.
- * <em>This API is experimental, and subject to change.</em>
  */
 VALUE
 rb_mutex_owned_p(VALUE self)