bitmap API consistency

[Andy Shevchenko]

Hi!

Surprisingly discovered today that bitmap API is not consistent in some
cases (at least one I found recently).

bitmap_fill() sets area of bits in a bitmap.
bitmap_zero() clears them.

However, if _fill() does something sane, _zero() clears _all_ bits up to
word size (long).

I think it should be fixed to be consistent with _fill() variant.

Thoughts?

-- 
Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Intel Finland Oy