Changed "obj_under_cursor" for the movement cursor

* the function is not designed for use with it.

Code correction in Stats.cpp.

artifacts/scripting/sfall function notes.txt

@@ -578,6 +578,7 @@ Some utility/math functions are available:
 - onlyCritter: True - only checks critters and ignores their cover (roof tiles, walls, scenery, etc.)
                False - checks all objects (can't check critters under objects)
 - passing False to the includeDude argument will ignore dude_obj
+- NOTE: the function will always return 0 if the cursor is in movement mode (hexagon cursor)
 
 > object sfall_func0("loot_obj")
 - returns a pointer to the target object (container or critter) of the loot screen