Function 3Ah            Remove Directory (RMDIR)

    Removes (deletes) the specified subdirectory.

        Entry   AH    = 3Ah
                DS:DX = Pointer to ASCIIZ directory name

        Return  AX = Error code, if CF is set
                     | 03h Path not found
                     | 05h Access denied (root / directory not empty)
                     | 10h Cannot delete current directory

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    Function 3Ah removes the subdirectory whose path is specified in
    the zero-ended string at address DS:DX; the string length is
    limited to 64 characters. The string must be a valid DOS directory
    name and cannot contain wildcards.