ext4: replace i_delalloc_reserved_flag with EXT4_STATE_DELALLOC_RESERVED

Remove the short element i_delalloc_reserved_flag from the
ext4_inode_info structure and replace it a new bit in i_state_flags.
Since we have an ext4_inode_info for every ext4 inode cached in the
inode cache, any savings we can produce here is a very good thing from
a memory utilization perspective.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

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

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

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

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

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