AIO sparse fix (type of ki_flags)

Fix type issue reported by latest 'sparse': kiocb.ki_flags should be
"unsigned long" (not "long"), to match bitop type signature.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>