Update linux-initialization-4.md

typo

Initialization/linux-initialization-4.md

@@ -315,7 +315,7 @@ For example let's look at `set_cpu_possible`. As we passed `true` as the second
 cpumask_set_cpu(cpu, to_cpumask(cpu_possible_bits));
 ```
 
-will be called. First of all let's try to understand the `to_cpumask` macro. This macro casts a bitmap to a `struct cpumask *`. CPU masks provide a bitmap suitable for representing the set of CPU's in a system, one bit position per CPU number. CPU mask presented by the `cpu_mask` structure:
+will be called. First of all let's try to understand the `to_cpumask` macro. This macro casts a bitmap to a `struct cpumask *`. CPU masks provide a bitmap suitable for representing the set of CPU's in a system, one bit position per CPU number. CPU mask presented by the `cpumask` structure:
 
 ```C
 typedef struct cpumask { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t;