fault injection: correct function names in documentation

init_fault_attr_entries() should be init_fault_attr_dentries().

cleanup_fault_attr_entries() should be cleanup_fault_attr_dentries().

Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>