fix wrong capital

Booting/linux-bootstrap-2.md

@@ -237,7 +237,7 @@ if (cmdline_find_option_bool("debug"))
 		puts("early console in setup code\n");
 ```
 
-The definition of `puts` is in [tty.c](https://github.com/torvalds/linux/blob/master/arch/x86/boot/tty.c). As we can see it prints character by character in a loop by calling The `putchar` function. Let's look into the `putchar` implementation:
+The definition of `puts` is in [tty.c](https://github.com/torvalds/linux/blob/master/arch/x86/boot/tty.c). As we can see it prints character by character in a loop by calling the `putchar` function. Let's look into the `putchar` implementation:
 
 ```C
 void __attribute__((section(".inittext"))) putchar(int ch)