Fix spelling errors. Change the output message to be the same in every instance.

[awatne]

Hello.
I went through the asm_3 post and found a couple spelling errors. I also noticed that the output message wasn't the same in every instance, so I changed that too. This is how it appears the first time:

    WRONG_ARGC_MSG  db "Error: expected two command-line arguments", 10
    ;; Length of the WRONG_ARGC_MSG message
    WRONG_ARGC_MSG_LEN equ 43

I also saw that you use both 10 and 0xa for newline, but i didn't change that. I thought it was informative.

[klaudiagrz]

Hi @awatne ! 👋🏻

Thank you for the contribution, nice findings!