doc/extension.rdoc: wording fix w.r.t. volatile vs RB_GC_GUARD

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56411 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,7 @@
+Thu Oct 13 10:37:31 2016  Eric Wong  <e@80x24.org>
+
+	* doc/extension.rdoc: wording fix
+
 Thu Oct 13 00:39:08 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* test/ruby/test_array.rb (test_sort_bang_with_freeze): make a

doc/extension.rdoc

@@ -1854,8 +1854,7 @@ keyword in C.  RB_GC_GUARD has the following advantages:
 
 3. "volatile" implementations may be buggy/inconsistent in some
    compilers and architectures. RB_GC_GUARD is customizable for broken
-   systems/compilers without those without negatively affecting other
-   systems.
+   systems/compilers without negatively affecting other systems.
 
 :enddoc: Local variables:
 :enddoc: fill-column: 70