Correctly state what jl_atexit_hook calls (#29833)

Author: tkf

doc/src/devdocs/init.md

@@ -220,7 +220,7 @@ the stack now rapidly unwinds back to `main()`.
 ## `jl_atexit_hook()`
 
 `main()` calls [`jl_atexit_hook()`](https://github.com/JuliaLang/julia/blob/master/src/init.c).
-This calls `_atexit` for each module, then calls [`jl_gc_run_all_finalizers()`](https://github.com/JuliaLang/julia/blob/master/src/gc.c)
+This calls `Base._atexit`, then calls [`jl_gc_run_all_finalizers()`](https://github.com/JuliaLang/julia/blob/master/src/gc.c)
 and cleans up libuv handles.
 
 ## `julia_save()`