Revert "fs: fix missing declaration of init_files"

This reverts commit bb00b119 which is
commit 2b2fc0be upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: Ib6926beda39531de3e1a1025b981b560535347a4
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>