Replace open-coded rate limiting logic with __ratelimit().
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@ozlabs.org
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>