Fix LuaJIT API docs for LUAJIT_MODE_*.

Thanks to sunfishgao.

doc/ext_c_api.html

@@ -89,8 +89,8 @@ other Lua/C API functions).
 </p>
 <p>
 The third argument specifies the mode, which is 'or'ed with a flag.
-The flag can be <tt>LUAJIT_MODE_OFF</tt> to turn a feature on,
-<tt>LUAJIT_MODE_ON</tt> to turn a feature off, or
+The flag can be <tt>LUAJIT_MODE_OFF</tt> to turn a feature off,
+<tt>LUAJIT_MODE_ON</tt> to turn a feature on, or
 <tt>LUAJIT_MODE_FLUSH</tt> to flush cached code.
 </p>
 <p>