ext4: let fallocate handle inline data correctly

If we are punching hole in a file, we will return ENOTSUPP.
As for the fallocation of some extents, we will convert the
inline data to a normal extent based file first.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --cc fs/ext4/extents.c
Simple merge

diff --cc fs/ext4/inline.c
Simple merge

diff --cc fs/ext4/xattr.h
Simple merge