Fix always-false conditional thinko in documentation.

llvm-svn: 200289
diff --git a/clang/docs/LanguageExtensions.rst b/clang/docs/LanguageExtensions.rst
index d994479..0a90bb7 100644
--- a/clang/docs/LanguageExtensions.rst
+++ b/clang/docs/LanguageExtensions.rst
@@ -1432,7 +1432,7 @@
 .. code-block:: c++
 
   int isdigit(int c);
-  int isdigit(int c) __attribute__((enable_if(c <= -1 && c > 255, "chosen when 'c' is out of range"))) __attribute__((unavailable("'c' must have the value of an unsigned char or EOF")));
+  int isdigit(int c) __attribute__((enable_if(c <= -1 || c > 255, "chosen when 'c' is out of range"))) __attribute__((unavailable("'c' must have the value of an unsigned char or EOF")));
   
   void foo(char c) {
     isdigit(c);