x86: Use bitmap library functions

Use bitmap_set()/bitmap_clear() to fill/zero a region of a
bitmap instead of doing set_bit()/clear_bit() each bit.

This change has been tested with ioperm() and there's no
change in behavior.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
LKML-Reference: <1297867715-20394-1-git-send-email-akinobu.mita@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>