fixed grammar in linux-bootstrap-2.md, Heap Initialization section

Booting/linux-bootstrap-2.md

@@ -331,7 +331,7 @@ Then there is the `heap_end` calculation:
 ```c
 	heap_end = (char *)((size_t)boot_params.hdr.heap_end_ptr + 0x200);
 ```
-which means `heap_end_ptr` or `_end` + `512`(`0x200h`). And at the last is checked that whether `heap_end` is greater than `stack_end`. If it is then `stack_end` is assigned to `heap_end` to make them equal.
+which means `heap_end_ptr` or `_end` + `512`(`0x200h`). The last check is whether `heap_end` is greater than `stack_end`. If it is then `stack_end` is assigned to `heap_end` to make them equal.
 
 Now the heap is initialized and we can use it using the `GET_HEAP` method. We will see how it is used, how to use it and how the it is implemented in the next posts.