f2fs: do more sanity check on inode

There are several issues in sanity_check_inode():
- The code looks not clean, it checks extra_attr related condition
dispersively.
- It missed to check i_extra_isize w/ lower boundary
- It missed to check feature dependency: prjquota, inode_chksum,
inode_crtime, compression features rely on extra_attr feature.
- It's not necessary to check i_extra_isize due to it will only
be assigned to non-zero value if f2fs_has_extra_attr() is true
in do_read_inode().

Fix them all in this patch.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>