Tutorial diffs don't update loops type

[bnoordhuis]

The diffs on https://corsix.github.io/dynasm-doc/tutorial.html do not seem to mention that const char* loops[MAX_NESTING]; should be changed to unsigned loops[MAX_NESTING];. It has the right type in the final version in the Compiling section, however.

I couldn't quite figure out how to turn that into a pull request so I'm opening an issue instead. :-)