Several prototypes in inode.h are just defined but not actually
implemented and used, so remove them.

Link: http://lkml.kernel.org/r/57763787.4020706@huawei.comSigned-off-by: NJoseph Qi <joseph.qi@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>