il_alloc: fix free memory function
il_alloc: fix free memory function

bcampbell/DevIL,DentonW/DevIL,Agadoul/DevIL,DentonW/DevIL,bcampbell/DevIL,bcampbell/DevIL,DentonW/DevIL,Agadoul/DevIL,bcampbell/DevIL,DentonW/DevIL,bcampbell/DevIL,Agadoul/DevIL,Agadoul/DevIL,Agadoul/DevIL,Agadoul/DevIL,bcampbell/DevIL,DentonW/DevIL,DentonW/DevIL