LU-9384 ldiskfs: port extra isize patches to sles12sp2

LU-9384 ldiskfs: port extra isize patches to sles12sp2

Port 3 extra isize patches for sles12sp2 as below:

commit e3014d14a81edde488d9a6758eea8afc41752d2d
       "ext4: fixup free space calculations when expanding inodes"
commit 94405713889d4a9d341b4ad92956e4e2ec8ec2c2
       "ext4: replace bogus assertion in ext4_xattr_shift_entries()"
commit 887a9730614727c4fff7cb756711b190593fc1df
       "ext4: keep existing extra fields when inode expands"

Signed-off-by: Yang Sheng <yang.sheng@intel.com>
Change-Id: Iab0914d0010436aa26d99b78b2ae4acea783fb7d
Reviewed-on: https://review.whamcloud.com/27244
Tested-by: Jenkins
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>