LU-20 ldiskfs: remove spurious warning message

LU-20 ldiskfs: remove spurious warning message

Remove the spurious warning message that we added for the missing
extents option since the MDS never gets the extents option enabled,
nor do we want it to be enabled for the MDT filesystem either.

	ldiskfs_fill_super: extents feature not enabled on this
	filesystem, use tune2fs

Original-Commit: 6541ea42978e73e0262273f6bd5ce0b71689fdc2

Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Change-Id: I9d896258b89ec3db528db59094572daac8dccab0
Reviewed-on: http://review.whamcloud.com/4028
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Niu Yawei <yawei.niu@intel.com>