According to linux kernel commit <89c1e79eb30> ("linux/bitmap.h: improve
BITMAP_{LAST,FIRST}_WORD_MASK"), these two macro could be improved.
This patch takes this change and also move them all in header file.
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>