kernel.h: fix wrong usage of __ratelimit()

When __ratelimit() returns 1 this means that we can go ahead.

Signed-off-by: Yong Zhang <yong.zhang@windriver.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>