Fix MCA link

Links are \[text\](URL) in Markdown, not (text)[URL].

Booting/linux-bootstrap-2.md

@@ -444,7 +444,7 @@ int query_mca(void)
 }
 ```
 
-It fills  the `ah` register with `0xc0` and calls the `0x15` BIOS interruption. After the interrupt execution it checks  the [carry flag](http://en.wikipedia.org/wiki/Carry_flag) and if it is set to 1, the BIOS doesn't support (**MCA**)[https://en.wikipedia.org/wiki/Micro_Channel_architecture]. If carry flag is set to 0, `ES:BX` will contain a pointer to the system information table, which looks like this:
+It fills  the `ah` register with `0xc0` and calls the `0x15` BIOS interruption. After the interrupt execution it checks  the [carry flag](http://en.wikipedia.org/wiki/Carry_flag) and if it is set to 1, the BIOS doesn't support [**MCA**](https://en.wikipedia.org/wiki/Micro_Channel_architecture). If carry flag is set to 0, `ES:BX` will contain a pointer to the system information table, which looks like this:
 
 ```
 Offset  Size    Description