D1: std.md5: corrections for the given example

[downs]

Stewart Gordon wrote:
> downs wrote:
> <snip>
>> while (auto len = file.readBlock(buffer.ptr, buffer.sizeof))
> <snip>
> 
> md5_example_2.d(7): expression expected, not 'auto'
> md5_example_2.d(7): found 'len' when expecting ')'
> md5_example_2.d(7): found '=' instead of statement
> 
> (this is line 7 after I removed comments and blank lines from your edit)
> 
> Stewart.

God I'm stupid.

Sorry.

I guess I wish that worked.