LU-8444 tests: test for unsigned xattr inode number

LU-8444 tests: test for unsigned xattr inode number

The patch for "MRP-3025 Hitting "LDISKFS-fs error (device md66):
ldiskfs_xattr_inode_iget: error while reading EA inode -2147483347" on
large MDT volumes with large_xattr feature enabled."

Added test:
1. MDS should have more than 2G inodes
2. mdt fs should be created with large_xattr flag.
3. set inode_goal to get higher inode number allocated:
   echo 2147483947 > /sys/fs/ldiskfs/<device>/inode_goal
3. create a file
4. start adding hard links to that file

Test-Parameters: trivial testlist=conf-sanity
Signed-off-by: Artem Blagodarenko <artem.blagodarenko@seagate.com>
Seagate-bug-id: MRP-3378
Change-Id: Id9c0fe9d8047935e5cf5be1b9209a74588565f2e
Reviewed-on: https://review.whamcloud.com/21547
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Alexander Zarochentsev <c17826@cray.com>
Reviewed-by: Alexander Lezhoev <garson2@gmail.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>