[Analyzer] Rename test `iterator-modelling.cpp` to `iterator-modeling.cpp`

Typo fix.

diff --git a/clang/test/Analysis/iterator-modelling.cpp b/clang/test/Analysis/iterator-modeling.cpp
similarity index 100%
rename from clang/test/Analysis/iterator-modelling.cpp
rename to clang/test/Analysis/iterator-modeling.cpp