Remove usage and defintion of __INLINE__

Remove usage and defintion of __INLINE__

The __INLINE__ definition is used on one place in the code: sfio.h
In this header, some function are defined as inline functions when the
__INLINE__ definition is set. With the current configuration the
__INLINE__ definition is never set, and the inline functions are never
used. Changing the condition so that __INLINE__ does get set, results in
errors during the compilation process. Therefore this defintion can be
removed.