Fixup link in the mm/linux-mm-2.md

mm/linux-mm-2.md

@@ -166,7 +166,7 @@ struct resource iomem_resource = {
 };
 ```
 
-As I have mentioned before, `request_regions` is used to register I/O port regions and this macro is used in many [places](http://lxr.free-electrons.com/ident?i=request_region) in the kernel. For example let's look at [drivers/char/rtc.c](https://github.com/torvalds/linux/blob/master/char/rtc.c). This source code file provides the [Real Time Clock](http://en.wikipedia.org/wiki/Real-time_clock) interface in the linux kernel. As every kernel module, `rtc` module contains `module_init` definition:
+As I have mentioned before, `request_regions` is used to register I/O port regions and this macro is used in many [places](http://lxr.free-electrons.com/ident?i=request_region) in the kernel. For example let's look at [drivers/char/rtc.c](https://github.com/torvalds/linux/blob/master/drivers/char/rtc.c). This source code file provides the [Real Time Clock](http://en.wikipedia.org/wiki/Real-time_clock) interface in the linux kernel. As every kernel module, `rtc` module contains `module_init` definition:
 
 ```C
 module_init(rtc_init);