Avoid the costly notifier list in the pagefault path and call
the kprobes code directly.  The same change went into the 2.6.22
cycle for powerpc, 2s390 and sparc64 already.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>