M30 response is missing linefeed, "ok" therefore not on own line

This leads to the command not being acknowledged properly, leading to consecutive issues in host software waiting for an acknowledgement.

Without patch:

    Send: M30 test.g
    Recv: File deleted:test.gok

With patch:

    Send: M30 test.g
    Recv: File deleted:test.g
    Recv: ok